NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99
Route: GAVAGE                                                                                                     Time: 08:33:12

                                                    FINAL#1, CORE STUDY MICE




       Facility:  Battelle Columbus Laboratory

       Chemical CAS #:  126-98-7

       Lock Date:  06/26/98

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All




































                                                              Page   1



NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 6| 7| 7| 7| 6| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 9| 3| 4| 3| 3| 3| 0| 0| 2| 0| 3| 5| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3|             
                                           | 3| 1| 5| 1| 2| 2| 7| 9| 3| 4| 2| 3| 2| 1| 1| 2| 2| 2| 1| 1| 2| 1| 1| 5| 2|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Periesophageal Tissue, Inflammation, |                                                                          |             
           Chronic Active                  |       2                                                                  |             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |       2                                                                  |             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Epithelium, Ulcer                    |                                                                          |             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                                          |             
      Clear Cell Focus                     |                                                 X  X                     |             
      Eosinophilic Focus                   |                                                 X           X            |             
      Hematopoietic Cell Proliferation     |                                                             1            |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1           2  1  1        2     2        1  1  1  1  1     1  1  1  1|             
      Inflammation, Chronic Active         |    1     1     1  1           2     2  1  2  1  1  1  1  1     1  1     1|             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis                             |             2           4                                                |             
      Pigmentation                         |                            1  1     1     1  1     1                    1|             
      Tension Lipidosis                    |                                                                          |             
      Hepatocyte, Vacuolization Cytoplasmic| 1     2                 2                                                |             

                                            __________________________________________________________________________|             
   Mesentery                               |                   +  +  +        +     +        +  +  +                  |             
      Fibrosis                             |                      4                 2        2  2                     |             
      Inflammation, Chronic Active         |                      2                 3           1                     |             
      Mineralization                       |                                        1              2                  |             
      Fat, Necrosis                        |                      4                 4        4  4                     |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |                +                                                        +|             
      Gingival, Foreign Body               |                X                                                        X|             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |                2                                                        2|             
      Pharyngeal, Foreign Body             |                                                                          |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Acinus, Atrophy                      |                                                                          |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1     1           1  1     1     2        1  1  1  1  1  1  1  1      |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Diverticulum                         |                                                                          |             
      Epithelium, Hyperplasia              |    1                                   3                             3   |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 6| 7| 7| 7| 6| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 9| 3| 4| 3| 3| 3| 0| 0| 2| 0| 3| 5| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3|             
                                           | 3| 1| 5| 1| 2| 2| 7| 9| 3| 4| 2| 3| 2| 1| 1| 2| 2| 2| 1| 1| 2| 1| 1| 5| 2|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                                                      1   |             
      Epithelium, Ulcer                    |                                                                      2   |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                         1|             
      Epithelium, Erosion                  |                                                                          |             
      Glands, Ectasia                      |    1     1  1  2                       1  1  1                       1  1|             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Aorta, Mineralization                |                                                                          |             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                         1                                                |             
      Artery, Mineralization               |                                                                          |             
      Valve, Inflammation, Suppurative     | 4                                                                        |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hypertrophy                          |                                                                      2   |             
      Capsule, Hyperplasia                 | 2  2  2  2  2  2  2  2  1  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2  2  2  2  2  2  2  3     2  2  2  2  2  2  2     2  2  2  2  2  2     2|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  M  +  +  +  +  M  +  +  +  M  +  +  M  +  +  +  +  +  M  +  +  +  M|             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |                                                                      1   |             
      Pars Distalis, Cyst                  |                                                                          |             
      Pars Distalis, Hyperplasia           |                2                          2                    2     1   |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             
      Inflammation, Chronic Active         |                                                                          |             
      Follicle, Cyst                       |                2                             2           2               |             
      Follicular Cell, Hyperplasia         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1        1                                1                              |             
      Inflammation, Chronic Active         |                                                                   2      |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 6| 7| 7| 7| 6| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 9| 3| 4| 3| 3| 3| 0| 0| 2| 0| 3| 5| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3|             
                                           | 3| 1| 5| 1| 2| 2| 7| 9| 3| 4| 2| 3| 2| 1| 1| 2| 2| 2| 1| 1| 2| 1| 1| 5| 2|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |             2              2  2        2        2     2     4        2   |             
      Mineralization                       |                                                                          |             
      Pigmentation                         |    1              1                                            1         |             

                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hydrometra                           |    4              2        2  4  2     4  4  4              4  4  4      |             
      Inflammation, Chronic Active         | 3                                                                        |             
      Thrombosis                           | 4                                                                        |             
      Endometrium, Hyperplasia, Cystic     | 3        2  2  1     2  1           2                 2     1        2  1|             
      Endometrium, Hyperplasia             |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                   3                                      3               |             
      Myelofibrosis                        |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node                              |                         +        +                       +               |             
      Mediastinal, Hyperplasia, Lymphoid   |                                                                          |             
      Mediastinal, Infiltration Cellular,  |                                                                          |             
           Histiocyte                      |                                                                          |             
      Pancreatic, Fibrosis                 |                                                          2               |             
      Pancreatic, Hyperplasia, Lymphoid    |                                                          3               |             
      Pancreatic, Pigmentation             |                                                          2               |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                4                    3                          3        4|             
      Infiltration Cellular, Plasma Cell   |                                                                          |             
      Pigmentation                         |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectasia                              |                                        4     4                           |             
      Hemorrhage                           |                                        2     2                           |             
      Hyperplasia, Lymphoid                |                                              3                          4|             
      Pigmentation                         |                                        2                                 |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |    2           3  2  3        2                 2     2  3     2        3|             
      Hyperplasia, Lymphoid                |       2                                                                  |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |             2     1  2              2  2     2  2           1  1     1   |             
      Ectopic Parathyroid Gland            |             2                                                            |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Cystic                  |                                                          3     2         |             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                   4                                                      |             
      Epidermis, Ulcer                     |                   4                                                      |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 6| 7| 7| 7| 6| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 9| 3| 4| 3| 3| 3| 0| 0| 2| 0| 3| 5| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3|             
                                           | 3| 1| 5| 1| 2| 2| 7| 9| 3| 4| 2| 3| 2| 1| 1| 2| 2| 2| 1| 1| 2| 1| 1| 5| 2|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Osteosclerosis                       |                                                                         4|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                   +                                               +      |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                   2      |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                    1                     |             

                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                      +   |             
      Sciatic, Axon, Degeneration          |                                                                      2   |             

                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                      +   |             
      Demyelination                        |                                                                      2   |             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |       2                                                                  |             
      Mineralization                       |                                              1              1            |             
      Pigmentation                         |                                                          1               |             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                   3      |             
      Artery, Mediastinum, Mineralization  |                                                                          |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     |                                                 +        +               |             
      Atrophy                              |                                                 4                        |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |          +                                               +               |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accumulation, Hyaline Droplet        |                         3        3                                       |             
      Infarct, Multiple                    | 2                                                                        |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  1  1     1  1           2     1     1  1  2     1  1  1  1  1     2|             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                                                             1            |             
      Nephropathy                          |                1                       2     1  2  2  1     1           1|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 5| 7| 6| 7| 7| 7| 6| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7|             
                             DAY ON TEST   | 9| 3| 4| 3| 3| 3| 0| 0| 2| 0| 3| 5| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 2| 3|             
                                           | 3| 1| 5| 1| 2| 2| 7| 9| 3| 4| 2| 3| 2| 1| 1| 2| 2| 2| 1| 1| 2| 1| 1| 5| 2|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Capsule, Mineralization              |                                                                          |             
      Cortex, Cyst                         |                                                                          |             
      Papilla, Inflammation, Acute         | 2                                                                        |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    2  1  1  1  1              1     1     1     4     1  1        1     1|             
      Inflammation, Chronic Active         |                                                                          |             
      Pigmentation                         |                                                 2                        |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 3| 6| 7| 4| 7| 7|            |
                             DAY ON TEST   | 6| 3| 3| 8| 3| 3| 7| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 6| 6| 3| 9| 3| 3|            |
                                           | 2| 2| 1| 7| 2| 1| 1| 2| 2| 1| 7| 2| 1| 1| 2| 2| 2| 2| 2| 2| 8| 2| 2| 1| 1|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Periesophageal Tissue, Inflammation, |                                                                          |            |
           Chronic Active                  |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|  49        |
      Inflammation, Chronic Active         |                                                                         4|      1  4.0|
      Epithelium, Ulcer                    |                                                                         4|      1  4.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                     X                                    |      1     |
      Clear Cell Focus                     |                                  X                                       |      3     |
      Eosinophilic Focus                   |    X  X  X                       X     X     X     X                     |      9     |
      Hematopoietic Cell Proliferation     |                                                 2                        |      2  1.5|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |    2  1     1  1     1        1     1  1  1  2     1  2        2     1  1|     30  1.2|
      Inflammation, Chronic Active         |    1  1     1  2     1  1        1  1  1     1  1  1  1        1     1  1|     32  1.1|
      Mixed Cell Focus                     |    X           X                 X                                       |      3     |
      Necrosis                             |                                                 1                        |      3  2.3|
      Pigmentation                         |    1  1     1  1     1           1     1     1  1  1                    1|     18  1.0|
      Tension Lipidosis                    |                         X     X                                          |      2     |
      Hepatocyte, Vacuolization Cytoplasmic|                         2     1                    2              2      |      7  1.7|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                      +     +  +     +     +  +        +     +            |  16        |
      Fibrosis                             |                      2        3     3     2                              |      8  2.5|
      Inflammation, Chronic Active         |                      2              2                                    |      5  2.0|
      Mineralization                       |                      2        1     2                                    |      5  1.6|
      Fat, Necrosis                        |                      4        4     4     4                              |      8  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                             +            |   3        |
      Gingival, Foreign Body               |                                                                          |      2     |
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           |                                                                          |      2  2.0|
      Pharyngeal, Foreign Body             |                                                             X            |      1     |

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Acinus, Atrophy                      |                            4                                             |      1  4.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 3| 6| 7| 4| 7| 7|            |
                             DAY ON TEST   | 6| 3| 3| 8| 3| 3| 7| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 6| 6| 3| 9| 3| 3|            |
                                           | 2| 2| 1| 7| 2| 1| 1| 2| 2| 1| 7| 2| 1| 1| 2| 2| 2| 2| 2| 2| 8| 2| 2| 1| 1|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  2  1  1           1  1     1  1  1     1        1           1        1|     27  1.1|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Diverticulum                         |                                  X                                       |      1     |
      Epithelium, Hyperplasia              |                                                                          |      3  2.3|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                                          |      1  1.0|
      Epithelium, Ulcer                    |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                                                                          |      1  1.0|
      Epithelium, Erosion                  |          2                                                               |      1  2.0|
      Glands, Ectasia                      |                      1  1           1        1  1        1  1            |     16  1.1|

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Aorta, Mineralization                |                   2                                                      |      1  2.0|

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                                                                          |      1  1.0|
      Artery, Mineralization               |                   2                                                      |      1  2.0|
      Valve, Inflammation, Suppurative     |                                                                          |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hypertrophy                          |                                                                          |      1  2.0|
      Capsule, Hyperplasia                 | 2  2  2  1  2  2  1  2  2        2  2  2  2  2  3  2  2  1  2  3  2  2  2|     48  2.0|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                                     2                                    |      1  2.0|

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2     2  2  2  2     2  2        2  2  2  2     2  2  2     2  2  2  2  2|     41  2.0|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  +  M  +  +  +  +  M  +  M  +  +  +  +  +  +  +  +  +  M  +|  39        |

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Angiectasis           |          1                                                               |      2  1.0|
      Pars Distalis, Cyst                  |                                              1                           |      1  1.0|
      Pars Distalis, Hyperplasia           |          1  1  1              2                                      2   |      9  1.6|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                      1                                                   |      1  1.0|
      Inflammation, Chronic Active         |                               2                                          |      1  2.0|
      Follicle, Cyst                       |       2                                                        2         |      5  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 3| 6| 7| 4| 7| 7|            |
                             DAY ON TEST   | 6| 3| 3| 8| 3| 3| 7| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 6| 6| 3| 9| 3| 3|            |
                                           | 2| 2| 1| 7| 2| 1| 1| 2| 2| 1| 7| 2| 1| 1| 2| 2| 2| 2| 2| 2| 8| 2| 2| 1| 1|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Follicular Cell, Hyperplasia         |                               2                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                            1                                             |      4  1.0|
      Inflammation, Chronic Active         |                                  1                                       |      2  1.5|

                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |    3     4     2  2                 3           4     3              4  2|     17  2.6|
      Mineralization                       |                         2                             2                  |      2  2.0|
      Pigmentation                         |       2                                2        2        2               |      7  1.6|

                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hydrometra                           | 2  4  4     4     2  4     3        2  1  4                    3        3|     23  3.2|
      Inflammation, Chronic Active         |                                                                          |      1  3.0|
      Thrombosis                           |                                                                          |      1  4.0|
      Endometrium, Hyperplasia, Cystic     |    2     1     2  2  2  2     2  2  1  2     2  2     1        2     3  2|     27  1.8|
      Endometrium, Hyperplasia             |                                                 2                        |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      2  3.0|
      Myelofibrosis                        |                               2  3                                       |      2  2.5|

                                            __________________________________________________________________________|____________|
   Lymph Node                              |             +              +        +        +        +     +            |   9        |
      Mediastinal, Hyperplasia, Lymphoid   |                                     4                                    |      1  4.0|
      Mediastinal, Infiltration Cellular,  |                                                                          |            |
           Histiocyte                      |                            4                                             |      1  4.0|
      Pancreatic, Fibrosis                 |                                                                          |      1  2.0|
      Pancreatic, Hyperplasia, Lymphoid    |                                                                          |      1  3.0|
      Pancreatic, Pigmentation             |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia, Lymphoid                |                                                 2                        |      5  3.2|
      Infiltration Cellular, Plasma Cell   |                                                 3                        |      1  3.0|
      Pigmentation                         |       2           2                    2                                 |      3  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +|  47        |
      Ectasia                              |                                                                          |      2  4.0|
      Hemorrhage                           |                                                                          |      2  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 3| 6| 7| 4| 7| 7|            |
                             DAY ON TEST   | 6| 3| 3| 8| 3| 3| 7| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 6| 6| 3| 9| 3| 3|            |
                                           | 2| 2| 1| 7| 2| 1| 1| 2| 2| 1| 7| 2| 1| 1| 2| 2| 2| 2| 2| 2| 8| 2| 2| 1| 1|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia, Lymphoid                |                                                                          |      2  3.5|
      Pigmentation                         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     | 2     2     3           3  3                    3           2           3|     18  2.5|
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  M  +  +|  47        |
      Cyst                                 |    2        2  2     1  2        1     2                 2     2        2|     20  1.7|
      Ectopic Parathyroid Gland            |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  49        |
      Hyperplasia, Cystic                  |                                                 4                        |      3  3.0|

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  4.0|
      Epidermis, Ulcer                     |                                                                          |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Osteosclerosis                       |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                            +                    +                        |   4        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                      1                                                   |      2  1.0|

                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                                          |   1        |
      Sciatic, Axon, Degeneration          |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Spinal Cord                             |                                                                          |   1        |
      Demyelination                        |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                              1                           |      2  1.5|
      Mineralization                       | 1                 1              1                                       |      5  1.0|
      Pigmentation                         |                                                                          |      1  1.0|
      Alveolar Epithelium, Hyperplasia     |                                                                1         |      1  1.0|
      Alveolus, Infiltration Cellular,     |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 6| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 3| 6| 7| 4| 7| 7|            |
                             DAY ON TEST   | 6| 3| 3| 8| 3| 3| 7| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3| 3| 6| 6| 3| 9| 3| 3|            |
                                           | 2| 2| 1| 7| 2| 1| 1| 2| 2| 1| 7| 2| 1| 1| 2| 2| 2| 2| 2| 2| 8| 2| 2| 1| 1|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
           Histiocyte                      |                                                                          |      1  3.0|
      Artery, Mediastinum, Mineralization  |                   2                                                      |      1  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            | 2                                                                        |      1  2.0|

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   2        |
      Atrophy                              |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                         +        +                                       |   4        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accumulation, Hyaline Droplet        |                                                                          |      2  3.0|
      Infarct, Multiple                    |                                                                          |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1     2  1     1  1  1  1  1  2  2  2     1  1  1        2     1  1|     35  1.2|
      Inflammation, Chronic Active         |          1                                                               |      1  1.0|
      Mineralization                       |                   1        1           1                             1   |      5  1.0|
      Nephropathy                          | 2  1                    1        1     1        2                       1|     15  1.3|
      Capsule, Mineralization              |                   2                                                      |      1  2.0|
      Cortex, Cyst                         |                      2     2                                             |      2  2.0|
      Papilla, Inflammation, Acute         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |          1     1  1  1  1  1     1  1  1  1  1  1  1     1     2         |     28  1.2|
      Inflammation, Chronic Active         |                                                       4                  |      1  4.0|
      Pigmentation                         |                                                                          |      1  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 6| 6| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 6| 7| 3| 2| 3| 3| 3| 0| 3| 4| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3|             
                                           | 0| 1| 2| 0| 8| 7| 6| 1| 1| 1| 2| 2| 9| 1| 4| 2| 2| 1| 2| 2| 0| 1| 1| 1| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ulcer                                |    4                                                                     |             
      Epithelium, Inflammation, Suppurative|    4                                                                     |             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Basophilic Focus                     | X     X  X                                         X  X           X      |             
      Clear Cell Focus                     |                         X           X        X        X  X               |             
      Eosinophilic Focus                   |          X                       X                                       |             
      Hematopoietic Cell Proliferation     |    2                                                                 1   |             
      Hepatodiaphragmatic Nodule           |                                                                   X      |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1     1  1           1     1  1  1  1     1  1  1  1  1  1  1     1  1  1|             
      Inflammation, Chronic Active         | 1     1  1  1  2     1  1  1  1  1     1     1  1  1  1  1  1     1  1   |             
      Mixed Cell Focus                     |                                                                          |             
      Necrosis                             |                                                 2                        |             
      Pigmentation                         |    1  1  1           1     1  1  1     1        1                        |             
      Tension Lipidosis                    |                               X                                          |             
      Hepatocyte, Vacuolization Cytoplasmic|                2           1  1                 2                        |             

                                            __________________________________________________________________________|             
   Mesentery                               | +  +        +                                +              +            |             
      Fibrosis                             | 2  2        2                                               2            |             
      Hemorrhage                           |                                              4                           |             
      Inflammation, Chronic Active         | 2           2                                               3            |             
      Mineralization                       | 2  2        2                                               3            |             
      Fat, Necrosis                        | 4  4        4                                               4            |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                                 +                 +      |             
      Gingival, Foreign Body               |                                                 X                 X      |             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |                                                 1                 2      |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1     1  1           1  1  1  1  1        2  1  2  1  1     1     1  1  1|             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperkeratosis                       |                                        4                                 |             
      Epithelium, Hyperplasia              |          2                                                        2      |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                        1                                 |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 6| 6| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 6| 7| 3| 2| 3| 3| 3| 0| 3| 4| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3|             
                                           | 0| 1| 2| 0| 8| 7| 6| 1| 1| 1| 2| 2| 9| 1| 4| 2| 2| 1| 2| 2| 0| 1| 1| 1| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Epithelium, Ulcer                    |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectopic Tissue                       |                                                                          |             
      Mineralization                       |                                                                          |             
      Epithelium, Dysplasia                |                                                                          |             
      Glands, Ectasia                      |          1                          2              1     1           1   |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Valve, Inflammation, Chronic Active  |                4                                                         |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                         1                                                |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             
      Capsule, Hyperplasia                 | 2  2  2  2  2  2     2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  1  2|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2     2  2  2  2     2  2  2  2     2  2     2        2  2  2     2  2  2|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +|             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |                      3                                                   |             
      Pars Distalis, Hemorrhage            |                                                                          |             
      Pars Distalis, Hyperplasia           |                                        2     2  3                    2  1|             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      C-Cell, Hyperplasia                  |                                                                          |             
      Follicle, Cyst                       |                                     2  2                                 |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                    1                     |             
      Inflammation, Chronic Active         |                                                                          |             
      Pigmentation                         |                                                                          |             

                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                             3            |             
      Cyst                                 |          4                 2     2                    3  2  3     4      |             
      Hemorrhage                           |                                                                          |             
      Mineralization                       |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 6| 6| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 6| 7| 3| 2| 3| 3| 3| 0| 3| 4| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3|             
                                           | 0| 1| 2| 0| 8| 7| 6| 1| 1| 1| 2| 2| 9| 1| 4| 2| 2| 1| 2| 2| 0| 1| 1| 1| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Pigmentation                         |       2              2           2  2     2  1     2  2                 2|             
      Thrombosis                           |                                                                          |             

                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hydrometra                           | 4        3     3  2     2  2        4  4     4  3        2  2  3  2  3  3|             
      Inflammation, Suppurative            |                                                                          |             
      Pigmentation                         |                                  2                                       |             
      Endometrium, Hyperplasia, Cystic     |       2  3     2     3     2  2              2  2  2  3  1     2  2      |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    4                                                                     |             
      Myelofibrosis                        |                                                                   2      |             

                                            __________________________________________________________________________|             
   Lymph Node                              |    +     +                          +                                    |             
      Lumbar, Ectasia                      |    3                                                                     |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                              3           4               |             
      Pigmentation                         | 1  1  1           2           2              1  1           1  2     2   |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  I  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                              2                           |             
      Inflammation, Chronic Active         |                                                                      4   |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     | 2  3     2     4        4     2        2  2  3  2  2        2        3   |             
      Hyperplasia, Lymphoid                |                                                                          |             
      Necrosis                             |                2                                                         |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  +|             
      Cyst                                 |       2  3              2        2           2              2     2     2|             
      Ectopic Parathyroid Gland            |       2                                                                  |             
      Thymocyte, Necrosis                  |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Cystic                  |                                                                          |             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Inflammation, Chronic Active         |                1                                                         |             
      Meninges, Hemorrhage                 |                3                                                         |             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 6| 6| 4| 7| 5| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 6| 7| 3| 2| 3| 3| 3| 0| 3| 4| 3| 3| 3| 3| 3| 3| 2| 3| 3| 3|             
                                           | 0| 1| 2| 0| 8| 7| 6| 1| 1| 1| 2| 2| 9| 1| 4| 2| 2| 1| 2| 2| 0| 1| 1| 1| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                3                                                         |             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |    1                                                                     |             
      Thrombosis                           |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |                                           2                              |             
      Mediastinum, Mineralization          |                                     3                                    |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     |                                                                +         |             
      Atrophy                              |                                                                4         |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |             +                                   +                        |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accumulation, Hyaline Droplet        |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  2     1  2     1  1  1  1  1  3  1  1  2  2  1  1  1  1     1  1  1|             
      Inflammation, Chronic Active         |                2                                                         |             
      Mineralization                       |       1     1                                                            |             
      Nephropathy                          | 2     2  3  2              1        1           1     1  1        1     1|             
      Cortex, Cyst                         |       3                                                              1   |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1           1  1           1                 2  2  1  1  1        1     1|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 7| 3| 5| 7| 7| 7| 7| 7| 7| 4| 2| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 5| 3| 3| 7| 6| 3| 3| 3| 1| 2| 3| 0| 8| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3|            |
                                           | 1| 6| 2| 2| 4| 8| 1| 2| 1| 1| 2| 1| 5| 9| 1| 1| 2| 2| 1| 2| 1| 0| 1| 0| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Ulcer                                |                                                                          |      1  4.0|
      Epithelium, Inflammation, Suppurative|                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                           3                              |      1  3.0|
      Basophilic Focus                     |                                                 X                        |      7     |
      Clear Cell Focus                     |                                              X                           |      6     |
      Eosinophilic Focus                   |                                                          X               |      3     |
      Hematopoietic Cell Proliferation     |                                                                          |      2  1.5|
      Hepatodiaphragmatic Nodule           |                                                                          |      1     |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1     1           1  1  1  1  1        1  1  1  1  1  1  1  1  2     1|     36  1.0|
      Inflammation, Chronic Active         | 1  1  1  1        1  1  1        1        1  1  1     1  1  1  1     1  1|     36  1.0|
      Mixed Cell Focus                     |                                           X                              |      1     |
      Necrosis                             |                                           2                              |      2  2.0|
      Pigmentation                         | 1                                1                                      1|     12  1.0|
      Tension Lipidosis                    |    X                                                                    X|      3     |
      Hepatocyte, Vacuolization Cytoplasmic|             2  1     1        4                                2         |      9  1.8|

                                            __________________________________________________________________________|____________|
   Mesentery                               | +     +           +              +     +  +                              |  11        |
      Fibrosis                             |                   2              2        3                              |      7  2.1|
      Hemorrhage                           |                                                                          |      1  4.0|
      Inflammation, Chronic Active         | 3                                2        3                              |      6  2.5|
      Mineralization                       | 2                 2                       2                              |      7  2.1|
      Fat, Necrosis                        |                   4              4        4                              |      7  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |          +                                +                    +         |   5        |
      Gingival, Foreign Body               |          X                                X                    X         |      5     |
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           |          2                                2                    2         |      5  1.8|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 2        2           1     1  1  2                    1  2  1  1  1     1|     29  1.2|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 7| 3| 5| 7| 7| 7| 7| 7| 7| 4| 2| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 5| 3| 3| 7| 6| 3| 3| 3| 1| 2| 3| 0| 8| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3|            |
                                           | 1| 6| 2| 2| 4| 8| 1| 2| 1| 1| 2| 1| 5| 9| 1| 1| 2| 2| 1| 2| 1| 0| 1| 0| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperkeratosis                       |                                                                          |      1  4.0|
      Epithelium, Hyperplasia              |                                                                          |      2  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                               2                                          |      2  1.5|
      Epithelium, Ulcer                    |                               4                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Ectopic Tissue                       |                                                                      2   |      1  2.0|
      Mineralization                       |          1                                                               |      1  1.0|
      Epithelium, Dysplasia                |                                                                      3   |      1  3.0|
      Glands, Ectasia                      | 1     1  1                                                     1         |      9  1.1|

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Valve, Inflammation, Chronic Active  |                                                                          |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                    1                     |      1  1.0|
      Capsule, Hyperplasia                 | 2  2  2  2  1  1  2  2  2  2  2  2  2     2  2  2  2  2  2  2  2  2  2  2|     48  1.9|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2  2  2  2        2  2  2  2  2     2        2  2     2  2  2  2  2  2  2|     37  2.0|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  M  +  +  +  M  +  +  +  +  +  M  M  +  +  +  M  +  M  +  +  M  M  +|  39        |

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Angiectasis           |                         1                                1               |      3  1.7|
      Pars Distalis, Hemorrhage            |                            4                                             |      1  4.0|
      Pars Distalis, Hyperplasia           |                1  2     2                                1     1     2  2|     12  1.8|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      C-Cell, Hyperplasia                  |                      3                                                   |      1  3.0|
      Follicle, Cyst                       |                                  2                                       |      3  2.0|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 7| 3| 5| 7| 7| 7| 7| 7| 7| 4| 2| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 5| 3| 3| 7| 6| 3| 3| 3| 1| 2| 3| 0| 8| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3|            |
                                           | 1| 6| 2| 2| 4| 8| 1| 2| 1| 1| 2| 1| 5| 9| 1| 1| 2| 2| 1| 2| 1| 0| 1| 0| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                         1                                                |      2  1.0|
      Inflammation, Chronic Active         |                                                                2         |      1  2.0|
      Pigmentation                         |                                                             2            |      1  2.0|

                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  3.0|
      Cyst                                 | 2                    2           2  4     2           2              2   |     14  2.6|
      Hemorrhage                           |                                     4                                    |      1  4.0|
      Mineralization                       |                      2           2  2                                    |      3  2.0|
      Pigmentation                         |                   2  2  1  1        2                 2           1      |     16  1.8|
      Thrombosis                           |                                     3                                    |      1  3.0|

                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hydrometra                           | 3  4  4              3           4  3     4  3  4     4  4        3      |     28  3.2|
      Inflammation, Suppurative            |    3                                                                     |      1  3.0|
      Pigmentation                         |                                                                          |      1  2.0|
      Endometrium, Hyperplasia, Cystic     | 2        2        2     1     2  1  2        2              1  1     2   |     24  1.9|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                4         |      2  4.0|
      Myelofibrosis                        |                                                 2                    3   |      3  2.3|

                                            __________________________________________________________________________|____________|
   Lymph Node                              |       +                                +                          +      |   6        |
      Lumbar, Ectasia                      |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  49        |
      Hyperplasia, Lymphoid                | 4                                                           4            |      4  3.8|
      Pigmentation                         | 1     2  2                    2                       2           2      |     16  1.6|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |       2                    3        2              3  2  2  2  3        2|     22  2.5|
      Hyperplasia, Lymphoid                | 2        2        2                                                      |      3  2.0|
      Necrosis                             |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  M  +  +  +  M|  43        |
      Cyst                                 |    2        2     2  1           1        2           2  1     2         |     17  1.9|
      Ectopic Parathyroid Gland            |                                                                          |      1  2.0|
      Thymocyte, Necrosis                  |    4                                                                     |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 7| 3| 5| 7| 7| 7| 7| 7| 7| 4| 2| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 5| 3| 3| 7| 6| 3| 3| 3| 1| 2| 3| 0| 8| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3|            |
                                           | 1| 6| 2| 2| 4| 8| 1| 2| 1| 1| 2| 1| 5| 9| 1| 1| 2| 2| 1| 2| 1| 0| 1| 0| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 INTEGUMENTARY SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia, Cystic                  |                            3                                             |      1  3.0|

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                    +                     |   1        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                        2                                 |      1  2.0|
      Inflammation, Chronic Active         |                                                                          |      1  1.0|
      Meninges, Hemorrhage                 |                                                                          |      1  3.0|

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      1  3.0|
      Inflammation, Chronic Active         |                                                    1                     |      1  1.0|
      Mineralization                       |                                                                          |      1  1.0|
      Thrombosis                           |             2                                                            |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                                                          |      1  2.0|
      Mediastinum, Mineralization          |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
      Atrophy                              |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accumulation, Hyaline Droplet        |                                                    3                     |      1  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  2  1     1  1  1  2  1  1        1  2  1  1     1  1  1     1  1|     42  1.2|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
      Mineralization                       |                               1                 1                       1|      5  1.0|
      Nephropathy                          | 2        1                       1           1        1     1  2        1|     19  1.4|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 7| 7| 3| 5| 7| 7| 7| 7| 7| 7| 4| 2| 7| 7| 7| 4| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 5| 3| 3| 7| 6| 3| 3| 3| 1| 2| 3| 0| 8| 3| 3| 3| 2| 3| 3| 3| 3| 3| 3| 3|            |
                                           | 1| 6| 2| 2| 4| 8| 1| 2| 1| 1| 2| 1| 5| 9| 1| 1| 2| 2| 1| 2| 1| 0| 1| 0| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 URINARY SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Cortex, Cyst                         |                                                                   3      |      3  2.3|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1     2  1  1  1  1  2  1  1  1        1  1     1  1     1  1  1  1  1|     31  1.1|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 5| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 8| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3|             
                                           | 1| 0| 2| 2| 1| 2| 2| 2| 1| 1| 3| 9| 3| 2| 1| 2| 2| 0| 2| 1| 1| 6| 2| 1| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                         1|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Metaplasia, Squamous                 |                                                    3                     |             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                                                          |             
      Basophilic Focus                     |          X                                                               |             
      Clear Cell Focus                     |                                           X  X                    X      |             
      Eosinophilic Focus                   |    X  X     X           X                                X               |             
      Hematopoietic Cell Proliferation     |                   1        1     1     1                          2      |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1        1  1  1  1  1              1  1     1  1  1  1     2     1|             
      Inflammation, Chronic Active         | 1  1  1  1  1  2  1  1  1  1     1        1  1     1  1  1  1            |             
      Mineralization                       |                                                                   4      |             
      Mixed Cell Focus                     |                                                                         X|             
      Necrosis                             |                                                                          |             
      Pigmentation                         |       1  1     1                          1                       2      |             
      Hepatocyte, Vacuolization Cytoplasmic|       2                                                                  |             

                                            __________________________________________________________________________|             
   Mesentery                               |    +        +                 +  +        +           +        +  +      |             
      Fibrosis                             |    3        2                             2           2                  |             
      Inflammation, Chronic Active         |    1                          2           2           1                  |             
      Mineralization                       |    1        1                 2  2        2           1           1      |             
      Pigmentation                         |                                           2                              |             
      Thrombosis                           |                                                                4         |             
      Fat, Necrosis                        |    4        4                    4        4           4                  |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |             +                                                            |             
      Gingival, Foreign Body               |                                                                          |             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |             2                                                            |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 2     2  1  1  1     2  1           1  1  1  2  1  2  1  1           1  2|             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                               1                                          |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 5| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 8| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3|             
                                           | 1| 0| 2| 2| 1| 2| 2| 2| 1| 1| 3| 9| 3| 2| 1| 2| 2| 0| 2| 1| 1| 6| 2| 1| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Epithelium, Hyperplasia              |                                                                          |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                                                          |             
      Epithelium, Ulcer                    |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Glands, Ectasia                      |                            1                          1  1  1            |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hypertrophy                          |                                                                          |             
      Capsule, Hyperplasia                 | 2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  1  2  3  2  2  2  1  2  2  2|             
      Zona Reticularis, Hyperplasia        |                                           2                              |             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2  2  2     2        2  2  2     2  2        2     2  2  2  2     2  2  2|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  M  M  +  M  +  +  M  +  M  M  +  M  M  M  +  +  +  +  +  +  M  M  +|             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |                                                             2            |             
      Pars Distalis, Cyst                  |          2                                                               |             
      Pars Distalis, Hyperplasia           |    2     2                                                  2            |             
      Pars Distalis, Pigmentation          |                                                                          |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectopic Thymus                       |                                                                          |             
      Follicle, Cyst                       |                         2                                                |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                               1                                          |             
      Duct, Cyst                           |                         3                    2                           |             

                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |    2  2  2     2        4  2           2     4                    4     2|             
      Hemorrhage                           |                         4                                      3  4      |             
      Mineralization                       |                      1  1                                                |             
      Pigmentation                         |                   2     1     2                 2           2     2     1|             
      Thrombosis                           |                         4                                      3  4      |             

                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 5| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 8| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3|             
                                           | 1| 0| 2| 2| 1| 2| 2| 2| 1| 1| 3| 9| 3| 2| 1| 2| 2| 0| 2| 1| 1| 6| 2| 1| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Hydrometra                           |             3  2     4  3        2  2        4  3     2           2  2  2|             
      Endometrium, Hyperplasia, Cystic     |    3  2  1  2  2  2     1        2     3  2           1  1  2     1      |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                  4              4                        |             

                                            __________________________________________________________________________|             
   Lymph Node                              |                   +        +     +     +                                 |             
      Lumbar, Hyperplasia, Lymphoid        |                                                                          |             
      Mediastinal, Hyperplasia, Lymphoid   |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  M  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                | 2                                                     4           4      |             
      Pigmentation                         |    2        2                                               2  2  2      |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |    2           2        2  2  4  3     3  2                       2      |             
      Hyperplasia, Lymphoid                |                                                                          |             
      Mineralization                       |                                                                   4      |             
      Pigmentation                         |                                                                   2      |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +|             
      Cyst                                 | 2  2     2     2           1              2  2        2  2              2|             
      Ectopic Parathyroid Gland            |                                                                          |             
      Hyperplasia, Lymphoid                |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Peripheral Nerve                        |                                                                          |             

                                            __________________________________________________________________________|             
   Spinal Cord                             |                                                                          |             
      Demyelination                        |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                                                                          |             
      Thrombosis                           |                                     2                                    |             
      Alveolar Epithelium, Hyperplasia     |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 5| 5| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 5| 8| 3| 3| 3| 3| 0| 3| 3| 3| 3| 1| 3| 3| 3|             
                                           | 1| 0| 2| 2| 1| 2| 2| 2| 1| 1| 3| 9| 3| 2| 1| 2| 2| 0| 2| 1| 1| 6| 2| 1| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM - cont                 |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +  +  +|             
      Hydronephrosis                       |                                                                3         |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1  1  1  1  2  1  1  1           1  1  1     2  1  1  1     1     1|             
      Mineralization                       |                               1                                   1      |             
      Nephropathy                          |       1     1           1  1              1                       1     1|             
      Pigmentation                         |                               2                                          |             
      Cortex, Cyst                         |                                                                          |             
      Renal Tubule, Casts Protein          |                                                                          |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1     1        1     1  1  1                 1     1  2     1           1|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 8| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3|            |
                                           | 9| 1| 0| 2| 1| 2| 2| 1| 2| 1| 1| 1| 0| 0| 2| 1| 0| 2| 1| 0| 0| 1| 2| 2| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Metaplasia, Squamous                 |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          |                                                       2                  |      1  2.0|
      Basophilic Focus                     |    X                                                                     |      2     |
      Clear Cell Focus                     |       X     X                                                     X      |      6     |
      Eosinophilic Focus                   | X  X                                      X        X              X  X   |     11     |
      Hematopoietic Cell Proliferation     |          1                                                               |      6  1.2|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  2  1  1  2  1  1  1  1  1  1  1  1     2  1  1  1  1  1  1  1  1|     40  1.1|
      Inflammation, Chronic Active         |    1  1  1  2  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  2  1  1  1|     41  1.1|
      Mineralization                       |                                                                          |      1  4.0|
      Mixed Cell Focus                     |                                              X           X               |      3     |
      Necrosis                             |          2                                            2                  |      2  2.0|
      Pigmentation                         |    1     1  1  1           1     1  1  1        1        1     1  1      |     17  1.1|
      Hepatocyte, Vacuolization Cytoplasmic|                                     2                                2   |      3  2.0|

                                            __________________________________________________________________________|____________|
   Mesentery                               |             +  +                    +              +  +     +  +         |  15        |
      Fibrosis                             |             3  2                    2              3        3  3         |     10  2.5|
      Inflammation, Chronic Active         |                                                    3  3     2  2         |      8  2.0|
      Mineralization                       |                2                    3              1        2  3         |     12  1.8|
      Pigmentation                         |                                                                          |      1  2.0|
      Thrombosis                           |                                                                          |      1  4.0|
      Fat, Necrosis                        |             4  4                    4              4        4  4         |     11  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                              +                           |   2        |
      Gingival, Foreign Body               |                                              X                           |      1     |
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           |                                              2                           |      2  2.0|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |                                                                         3|      1  3.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 8| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3|            |
                                           | 9| 1| 0| 2| 1| 2| 2| 1| 2| 1| 1| 1| 0| 0| 2| 1| 0| 2| 1| 0| 0| 1| 2| 2| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1     1        1        2     1  1  1  1  1     1  1  1  2  1         |     32  1.3|
      Inflammation, Chronic Active         |                1                                1                        |      2  1.0|
      Mineralization                       |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |             2                                                            |      1  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           | 2        1                                                               |      2  1.5|
      Epithelium, Ulcer                    | 4                                                                        |      1  4.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Glands, Ectasia                      |       1           1           1  1           1                       2   |     10  1.1|

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hypertrophy                          |                                     2                                    |      1  2.0|
      Capsule, Hyperplasia                 | 2  2  2  2  2  2  2  1  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2|     50  2.0|
      Zona Reticularis, Hyperplasia        |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2  2     2  2  2  2  2  2  2  2  2  2  2  2  2  2  2     2  2  2  2  2  2|     40  2.0|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  M  M  +  +  M|  34        |

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Angiectasis           |             2           2                 2                 1           1|      6  1.7|
      Pars Distalis, Cyst                  |          1                                                               |      2  1.5|
      Pars Distalis, Hyperplasia           |          2              2           2     2                 1  2        2|     10  1.9|
      Pars Distalis, Pigmentation          |                                              2                           |      1  2.0|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Ectopic Thymus                       |                                                             2            |      1  2.0|
      Follicle, Cyst                       |                                     2                             3      |      3  2.3|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 8| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3|            |
                                           | 9| 1| 0| 2| 1| 2| 2| 1| 2| 1| 1| 1| 0| 0| 2| 1| 0| 2| 1| 0| 0| 1| 2| 2| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                     1                 1                  |      3  1.0|
      Duct, Cyst                           |                                                                          |      2  2.5|

                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst                                 |          4           2  2        2           2        2  2           2   |     18  2.4|
      Hemorrhage                           |          4                                                               |      4  3.8|
      Mineralization                       |                                                                          |      2  1.0|
      Pigmentation                         |                2                 1           2           2               |     11  1.7|
      Thrombosis                           |                                                                          |      3  3.7|

                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hydrometra                           | 2  4  2  4  3     4  4  3  4     2     2     2  4  4  3  2     4  3  3   |     31  2.9|
      Endometrium, Hyperplasia, Cystic     |       2        2        2  2  2        2     1              2  2  2      |     24  1.8|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 4                                                        4               |      4  4.0|

                                            __________________________________________________________________________|____________|
   Lymph Node                              |          +  +                                   +        +               |   8        |
      Lumbar, Hyperplasia, Lymphoid        |          4                                                               |      1  4.0|
      Mediastinal, Hyperplasia, Lymphoid   |             2                                   3                        |      2  2.5|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                                                                          |      3  3.3|
      Pigmentation                         |       1     2                                            2              2|      9  1.9|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +|  47        |
      Hyperplasia, Lymphoid                |                                        4                                 |      1  4.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     | 3     2  3           3                       2           3               |     15  2.5|
      Hyperplasia, Lymphoid                |                      3                                                   |      1  3.0|
      Mineralization                       |                                                                          |      1  4.0|
      Pigmentation                         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Thymus                                  | M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|  46        |
      Cyst                                 |    2     3        1  2  2  2  2  2  2  2           2        2           2|     23  2.0|
      Ectopic Parathyroid Gland            |                                     1                                    |      1  1.0|
      Hyperplasia, Lymphoid                |       4     4                                                            |      2  4.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 8| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 0| 3| 3| 3| 3| 3| 3|            |
                                           | 9| 1| 0| 2| 1| 2| 2| 1| 2| 1| 1| 1| 0| 0| 2| 1| 0| 2| 1| 0| 0| 1| 2| 2| 2|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 MUSCULOSKELETAL SYSTEM - cont             |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         | +                                                     +                  |   2        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Peripheral Nerve                        |                                                       +                  |   1        |

                                            __________________________________________________________________________|____________|
   Spinal Cord                             | +                                                     +                  |   2        |
      Demyelination                        |                                                       3                  |      1  3.0|

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                              1  1     2                  |      3  1.3|
      Mineralization                       |                            1              1                              |      2  1.0|
      Thrombosis                           |                                                                          |      1  2.0|
      Alveolar Epithelium, Hyperplasia     |                                     2                                    |      1  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Harderian Gland                         | +                                                                 +      |   2        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hydronephrosis                       |                                                                          |      1  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  3  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1|     44  1.1|
      Mineralization                       |                                           1     1                       1|      5  1.0|
      Nephropathy                          | 2     1  3  1  1  1     1  1     1     1           1     1  1  2  1      |     22  1.2|
      Pigmentation                         |                                                                          |      1  2.0|
      Cortex, Cyst                         |             2                                                            |      1  2.0|
      Renal Tubule, Casts Protein          |          3                                                               |      1  3.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1        1  1  1  1  2     1  2  1  1  1  1     1     1        1  2  1|     29  1.1|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 3| 7| 6| 7| 7| 7| 7| 6| 5| 7| 4| 4| 4| 4| 4|             
                             DAY ON TEST   | 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 0| 3| 4| 3| 3| 3| 3| 4| 8| 3| 8| 8| 8| 8| 8|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 8| 1| 1| 1| 2| 2| 2| 1| 1| 1| 0| 0| 0| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia, Lymphoid | 3                                                                        |             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                                                                          |             
      Clear Cell Focus                     |                                                 X                        |             
      Eosinophilic Focus                   |                         X                                                |             
      Hematopoietic Cell Proliferation     |                                     1                                    |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1     1     1  1  1  1           1  1  1  1              1  1     1|             
      Inflammation, Chronic Active         | 1     1  1  1  1        1  1           1  1  1  1  1  1  1  1  1     1  1|             
      Mineralization                       |                                                                          |             
      Necrosis                             |                                                                          |             
      Pigmentation                         |                                                 1        1               |             
      Hepatocyte, Vacuolization Cytoplasmic| 1  1     1              1     2                             1  1     1  1|             

                                            __________________________________________________________________________|             
   Mesentery                               |                                  +                                       |             
      Fibrosis                             |                                  2                                       |             
      Mineralization                       |                                                                          |             
      Fat, Necrosis                        |                                  4                                       |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |                                                                          |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |       1                                                           2      |             
      Acinus, Hyperplasia                  |                                                    2                     |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  1           1  1  2  1           1        1  1  1        1  1      |             
      Inflammation, Chronic Active         |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                                                          |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
      Glands, Ectasia                      | 1  1                                                                     |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 3| 7| 6| 7| 7| 7| 7| 6| 5| 7| 4| 4| 4| 4| 4|             
                             DAY ON TEST   | 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 0| 3| 4| 3| 3| 3| 3| 4| 8| 3| 8| 8| 8| 8| 8|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 8| 1| 1| 1| 2| 2| 2| 1| 1| 1| 0| 0| 0| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Suppurative            |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Accessory Adrenal Cortical Nodule    |                                                                          |             
      Hematopoietic Cell Proliferation     |                                                                          |             
      Capsule, Hyperplasia                 | 2  2  2  2  2  2  2  2  2  2  1  2  2  2  2  1  2  2  2  2  2  2  2  2  2|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                                                          |             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Hyperplasia                          | 2  2  2     2     2  2     2        2  2     2              2  2  2  2  2|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  +  +  M  +  +  M  +  +  +  +|             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +|             
      Pars Distalis, Angiectasis           |                                        2  2                              |             
      Pars Distalis, Cyst                  |                                        2           1                     |             
      Pars Distalis, Hyperplasia           |                                        2  2  1                           |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                              1                           |             
      Follicle, Cyst                       |                                                 2                        |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Peritoneum                              |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                          1               |             
      Inflammation, Chronic Active         |                                                                          |             
      Duct, Cyst                           |                                                                          |             

                                            __________________________________________________________________________|             
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |          2                             3  2                              |             
      Hemorrhage                           |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             
      Mineralization                       |                                        2                                 |             
      Pigmentation                         |                                              1     1                     |             

                                            __________________________________________________________________________|             
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                  4                                       |             
      Hemorrhage                           |                                                                          |             
      Hydrometra                           | 2        2     2     2  2  2           4     3     3  4           2      |             
      Endometrium, Hyperplasia, Cystic     |    2     2  2  2  3  2  2        2        2  2  2                 1  1  1|             

                                            __________________________________________________________________________|             
   Vagina                                  |                                                          +               |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 3| 7| 6| 7| 7| 7| 7| 6| 5| 7| 4| 4| 4| 4| 4|             
                             DAY ON TEST   | 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 0| 3| 4| 3| 3| 3| 3| 4| 8| 3| 8| 8| 8| 8| 8|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 8| 1| 1| 1| 2| 2| 2| 1| 1| 1| 0| 0| 0| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                                     2                                    |             

                                            __________________________________________________________________________|             
   Lymph Node                              |                                                                          |             
      Lumbar, Ectasia                      |                                                                          |             
      Mediastinal, Inflammation            |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
      Pigmentation                         |                                                          2               |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  A  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                                  3                                       |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |             2                    2     1  2  2  2        2              2|             
      Thymocyte, Necrosis                  |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                         1                                                |             
      Necrosis                             |                                                                          |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                          |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     |          +                                               +               |             
      Atrophy                              |                                                                          |             
      Anterior Chamber, Infiltration       |                                                                          |             
          Cellular, Polymorphonuclear      |                                                          3               |             
      Cornea, Inflammation, Chronic Active |                                                          2               |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |                                                          +               |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 3| 7| 6| 7| 7| 7| 7| 6| 5| 7| 4| 4| 4| 4| 4|             
                             DAY ON TEST   | 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 0| 3| 4| 3| 3| 3| 3| 4| 8| 3| 8| 8| 8| 8| 8|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 8| 1| 1| 1| 2| 2| 2| 1| 1| 1| 0| 0| 0| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM - cont              |                                                                          |             
                                           |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  1  1  1  1        1  1     1     1  1  1  1        1  1     1  1  1|             
      Mineralization                       |          1                       1                                       |             
      Nephropathy                          |                                  1  1     1                       1      |             
      Cortex, Cyst                         |                                                 2                        |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |       1                 1        1  1           1  1        1  1  1  1   |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 2| 7| 3|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 1| 3| 3| 0| 3| 3| 3| 9| 1| 3| 4|            |
                                           | 2| 2| 1| 0| 2| 1| 2| 1| 1| 0| 2| 1| 3| 2| 4| 0| 1| 3| 1| 2| 1| 4| 2| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  48        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Peyer's Patch, Hyperplasia, Lymphoid |          3                                                               |      2  3.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |                                                 X                    X   |      2     |
      Clear Cell Focus                     |                                                                          |      1     |
      Eosinophilic Focus                   |                                        X                 X               |      3     |
      Hematopoietic Cell Proliferation     |                                                                1         |      2  1.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |    1  1  1  1  1  2  1  1        1  2  1     1           1  1        1   |     30  1.1|
      Inflammation, Chronic Active         | 1  1  1  1  1  1  1  1  2  1  1  1     1  2  1     2  1  1  1        1   |     38  1.1|
      Mineralization                       |                                                                         1|      1  1.0|
      Necrosis                             |                                                                         3|      1  3.0|
      Pigmentation                         |                         1     1        1     1           1               |      7  1.0|
      Hepatocyte, Vacuolization Cytoplasmic|       2  2  2     2     1        2     1                 2        1      |     18  1.4|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                               +     +        +                           |   4        |
      Fibrosis                             |                                              2                           |      2  2.0|
      Mineralization                       |                                              2                           |      1  2.0|
      Fat, Necrosis                        |                               4              4                           |      3  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             |                                                    +                     |   1        |

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      2  1.5|
      Acinus, Hyperplasia                  |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1     1  1  1  1     1  1  1        1     1  1     1     1     1      |     27  1.0|
      Inflammation, Chronic Active         |                                                    4                     |      1  4.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |                                                                3         |      1  3.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                                2         |      1  2.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 2| 7| 3|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 1| 3| 3| 0| 3| 3| 3| 9| 1| 3| 4|            |
                                           | 2| 2| 1| 0| 2| 1| 2| 1| 1| 0| 2| 1| 3| 2| 4| 0| 1| 3| 1| 2| 1| 4| 2| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Mineralization                       |                                                                         1|      1  1.0|
      Glands, Ectasia                      |       1                                                                  |      3  1.0|

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Suppurative            |                                                                         2|      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Accessory Adrenal Cortical Nodule    |       2              1                                                   |      2  1.5|
      Hematopoietic Cell Proliferation     |                                                    1                     |      1  1.0|
      Capsule, Hyperplasia                 | 2  2  3  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  1  2  1|     50  1.9|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                      3                                                   |      1  3.0|

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          | 2              2  2  2     2  2  2  2  2  2     2  3  2  2  2  2  2  2   |     33  2.0|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  M  M  +  +  +  +  M  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  M|  40        |

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Angiectasis           |                                                                          |      2  2.0|
      Pars Distalis, Cyst                  |                                                                          |      2  1.5|
      Pars Distalis, Hyperplasia           |       3        2              2  3     2  2  2     2                     |     11  2.1|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  1.0|
      Follicle, Cyst                       |             2                                         2  2               |      4  2.0|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Peritoneum                              |                                     +                                    |   1        |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  1.0|
      Inflammation, Chronic Active         |                                                 2                        |      1  2.0|
      Duct, Cyst                           |       2                                         3                        |      2  2.5|

                                            __________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |    3  2  2  2        3                                   3              4|     10  2.6|
      Hemorrhage                           |                                                                         2|      1  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 2| 7| 3|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 1| 3| 3| 0| 3| 3| 3| 9| 1| 3| 4|            |
                                           | 2| 2| 1| 0| 2| 1| 2| 1| 1| 0| 2| 1| 3| 2| 4| 0| 1| 3| 1| 2| 1| 4| 2| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
      Inflammation, Suppurative            |                                                                         2|      1  2.0|
      Mineralization                       |                                                                          |      1  2.0|
      Pigmentation                         |    1                                      2        2           2         |      6  1.5|

                                            __________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  4.0|
      Hemorrhage                           |                                  2                                       |      1  2.0|
      Hydrometra                           | 3  3     4                          2  4     2  4     4  4               |     20  2.9|
      Endometrium, Hyperplasia, Cystic     | 1     2  2  1  2  1     2  2  3  3  2     2  2        1     2  1     1  1|     32  1.8|

                                            __________________________________________________________________________|____________|
   Vagina                                  |                                                                          |   1        |

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node                              |                            +        +     +        +                 +   |   5        |
      Lumbar, Ectasia                      |                            4                                             |      1  4.0|
      Mediastinal, Inflammation            |                                                    2                     |      1  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +|  47        |
      Hyperplasia, Lymphoid                |                   2                                                      |      1  2.0|
      Pigmentation                         |    2                 2                                2                  |      4  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                   3                                                      |      1  3.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     |                2     2              2     3  2     3           3     2  4|     10  2.6|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M|  48        |
      Cyst                                 | 2  2     2  2     2     2  2     2              2           2     1      |     19  1.9|
      Thymocyte, Necrosis                  |                                                                   4      |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 6| 2| 7| 3|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 7| 3| 1| 3| 3| 0| 3| 3| 3| 9| 1| 3| 4|            |
                                           | 2| 2| 1| 0| 2| 1| 2| 1| 1| 0| 2| 1| 3| 2| 4| 0| 1| 3| 1| 2| 1| 4| 2| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Inflammation, Chronic Active         |                                                    2                     |      1  2.0|
      Mineralization                       |                         1                                                |      2  1.0|
      Necrosis                             |                                                    3                     |      1  3.0|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                      1                                         3         |      2  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                +              +                                          |   4        |
      Atrophy                              |                               4                                          |      1  4.0|
      Anterior Chamber, Infiltration       |                                                                          |            |
          Cellular, Polymorphonuclear      |                                                                          |      1  3.0|
      Cornea, Inflammation, Chronic Active |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                +                                                         |   2        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  1  1  1  1  1  1  1  1  1     1        1  1  1     1        1   |     35  1.0|
      Mineralization                       | 1           1                                      1                    2|      6  1.2|
      Nephropathy                          | 1           1                    1              1                    1   |      9  1.0|
      Cortex, Cyst                         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |    1  1     1           1  1  1  1     2  1     1        1     1         |     22  1.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 6| 7| 6| 7| 0| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 7| 9| 3| 0| 0| 2| 3| 2| 3| 3| 3| 3| 0| 7| 2| 3| 3| 5| 1| 7| 2| 3|             
                                           | 0| 1| 9| 0| 4| 1| 9| 0| 9| 0| 9| 0| 1| 0| 0| 1| 7| 9| 8| 0| 0| 2| 3| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Inflammation, Chronic Active         |                                                                2         |             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Angiectasis                          |                                           2                              |             
      Clear Cell Focus                     |                         X           X     X                             X|             
      Eosinophilic Focus                   |       X     X  X     X  X        X  X           X  X                     |             
      Hepatodiaphragmatic Nodule           |                X                                                         |             
      Infiltration Cellular, Mast Cell     |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |          3     1              1        1           1                     |             
      Inflammation, Chronic Active         |                1     1     1        1        3  2  1        2        1   |             
      Malformation                         |                                                                          |             
      Necrosis                             |          2                                   3              3            |             
      Pigmentation                         |    2                                               1                     |             
      Tension Lipidosis                    |                                                                          |             
      Hepatocyte, Vacuolization Cytoplasmic|       2                 1                    1                          2|             

                                            __________________________________________________________________________|             
   Mesentery                               |          +                                                               |             
      Fibrosis                             |                                                                          |             
      Inflammation, Chronic Active         |                                                                          |             
      Thrombosis                           |          4                                                               |             
      Fat, Necrosis                        |                                                                          |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             | +  +        +  +     +     +     +     +        +  +  +  +  +        +   |             
      Gingival, Foreign Body               | X  X        X  X     X     X     X              X  X  X  X  X        X   |             
      Gingival, Inflammation, Acute        |                      1                 1        1  1                     |             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |    1        2  1           2     2                    2  2  1        2   |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Granuloma                            |                                  2                                       |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |       1     1  1     1  1  1     1  1     1  1     1     1  1            |             
      Inflammation, Chronic                |                                  1                                       |             
      Mineralization                       |                                  1                                       |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Epithelium, Hyperplasia              |             2                                                            |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 6| 7| 6| 7| 0| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 7| 9| 3| 0| 0| 2| 3| 2| 3| 3| 3| 3| 0| 7| 2| 3| 3| 5| 1| 7| 2| 3|             
                                           | 0| 1| 9| 0| 4| 1| 9| 0| 9| 0| 9| 0| 1| 0| 0| 1| 7| 9| 8| 0| 0| 2| 3| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                              2                           |             
      Epithelium, Ulcer                    |                                              4                           |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Ulcer                                |                                                                          |             
      Epithelium, Erosion                  |    2                                                                     |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                                                          |             
      Glands, Ectasia                      |                            1        1  1  1                    1        1|             

                                            __________________________________________________________________________|             
   Tooth                                   |                                                 +                        |             
      Malformation                         |                                                 X                        |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I     +  +|             
      Inflammation, Chronic Active         |                                                             3            |             
      Mineralization                       |                                                             2            |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Degeneration, Fatty                  |                   1                                                      |             
      Hyperplasia                          |       3              1     1        2  3  3                             2|             
      Hypertrophy                          |       3     3     2           1  1  3  1  2  1     2  1     1           2|             
      Metaplasia, Osseous                  |       3                                                                  |             
      Capsule, Hyperplasia                 | 2     2  1  1  1     1  1  2        2  2  2  1  1  1  1     1  1        1|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Hyperplasia                          |          2                                                               |             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Hyperplasia                          | 2  1  3        2  2  2  2  2  2  3  3  2  2  3  3  2  2  2  2  2     2  3|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  +  M  +  M  +  M  +  +  +  +  M  +     +  +|             
      Cyst                                 |                               2                                          |             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  I  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Pars Distalis, Cyst                  |                                                                          |             
      Pars Distalis, Hyperplasia           |                            2                                             |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Follicle, Cyst                       |       3                    2                                             |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Atrophy                              |    3                                                                     |             
      Granuloma Sperm                      |    3                                                                     |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 6| 7| 6| 7| 0| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 7| 9| 3| 0| 0| 2| 3| 2| 3| 3| 3| 3| 0| 7| 2| 3| 3| 5| 1| 7| 2| 3|             
                                           | 0| 1| 9| 0| 4| 1| 9| 0| 9| 0| 9| 0| 1| 0| 0| 1| 7| 9| 8| 0| 0| 2| 3| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1        2  1  1     1                       1        1  1         |             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                                                             1            |             

                                            __________________________________________________________________________|             
   Penis                                   |             +                                                            |             
      Hemorrhage                           |             3                                                            |             

                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Atrophy                              |    3                                                                     |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1     1        2                    2           1  2           2        1|             
      Inflammation, Chronic Active         |                   2  4     1                 4                           |             
      Duct, Cyst                           |                2  2     3           3  3        2     3                 2|             

                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Atrophy                              |    3                                                                     |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1     1        1           1     1        1  1  1  2     1  1            |             

                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Atrophy                              |    3                                                                     |             

                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Mineralization                       |    2                                                                     |             
      Germinal Epithelium, Atrophy         |    4                                                                     |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Lymph Node                              |                                        +                                 |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Hyperplasia, Lymphoid                |       2                                                                  |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Hematopoietic Cell Proliferation     |                                                    2                     |             
      Hemorrhage                           |    3                                                                     |             
      Hyperplasia, Lymphoid                |                                                    3                     |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Inflammation, Granulomatous          |                                                                          |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Hematopoietic Cell Proliferation     |    3     3                                         2        4           2|             
      Hyperplasia, Lymphoid                |                2                                                         |             

                                            __________________________________________________________________________|             
   Thymus                                  | M  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  M  +  M  +  +  +     +  +|             
      Cyst                                 |             2                    2           2           2     1         |             
      Ectopic Parathyroid Gland            |             1                                                            |             
      Ectopic Thyroid                      |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M     M  M|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 6| 7| 6| 7| 0| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 7| 9| 3| 0| 0| 2| 3| 2| 3| 3| 3| 3| 0| 7| 2| 3| 3| 5| 1| 7| 2| 3|             
                                           | 0| 1| 9| 0| 4| 1| 9| 0| 9| 0| 9| 0| 1| 0| 0| 1| 7| 9| 8| 0| 0| 2| 3| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                2                                                         |             
      Inflammation, Chronic Active         |                                              2                           |             
      Mineralization                       |                                                             1           1|             
      Thrombosis                           |                      2                                      4            |             
      Alveolar Epithelium, Hyperplasia     |       2                    4                                             |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                                                          |             
      Bronchiole, Foreign Body             |                                              X                           |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Foreign Body                         |                                                       X                  |             
      Inflammation, Chronic Active         |                                                       2                  |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |    2                          1              1                           |             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     |                               +                                          |             
      Cornea, Inflammation, Suppurative    |                               2                                          |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |                +              +                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                1                                                         |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Infarct                              | 3                                         2                              |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1              1  1                 1     1        1     1  1        1   |             
      Inflammation, Chronic Active         |                                                                          |             
      Metaplasia, Osseous                  |          3                                                               |             
      Mineralization                       | 1     1  1  1  1        1  1  1  1  1  1  1  1  1  1     1  1  1     1  1|             
      Nephropathy                          | 1     1     2  1        1  2  1  1  2  2  2     2  1  3  1     2     1  1|             
      Cortex, Cyst                         |                2        2     2           2                          2  1|             
      Renal Tubule, Hyperplasia            |       2                             2     2                              |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 6| 6| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 5| 6| 7| 6| 7| 6| 7| 0| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 7| 9| 3| 0| 0| 2| 3| 2| 3| 3| 3| 3| 0| 7| 2| 3| 3| 5| 1| 7| 2| 3|             
                                           | 0| 1| 9| 0| 4| 1| 9| 0| 9| 0| 9| 0| 1| 0| 0| 1| 7| 9| 8| 0| 0| 2| 3| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    0 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Renal Tubule, Necrosis               |                                              2                           |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +     +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                1        1           1              1        1  1         |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 6| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 8| 6| 9| 3| 2| 3| 3| 3| 2| 9| 3| 3| 3| 3| 3| 2| 2| 3| 2| 1| 3| 3| 3| 2|            |
                                           | 1| 3| 3| 4| 1| 9| 0| 0| 1| 9| 4| 0| 1| 1| 0| 1| 9| 9| 0| 9| 3| 1| 0| 1| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Angiectasis                          |                                                                          |      1  2.0|
      Clear Cell Focus                     |                   X     X                                X               |      7     |
      Eosinophilic Focus                   |    X                             X  X           X        X     X  X      |     16     |
      Hepatodiaphragmatic Nodule           |                                                                          |      1     |
      Infiltration Cellular, Mast Cell     |       2                                                                  |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |          1     1                 1                          1            |      9  1.2|
      Inflammation, Chronic Active         | 1           2  1     1        2        1  1  1  1  1  1  1        1      |     22  1.3|
      Malformation                         |                                     2                                    |      1  2.0|
      Necrosis                             |    2     2                                                     2         |      6  2.3|
      Pigmentation                         |                                        2                                 |      3  1.7|
      Tension Lipidosis                    |                                                       X                  |      1     |
      Hepatocyte, Vacuolization Cytoplasmic|                            1           1                                 |      6  1.3|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                                        +                          +      |   3        |
      Fibrosis                             |                                                                   2      |      1  2.0|
      Inflammation, Chronic Active         |                                                                   2      |      1  2.0|
      Thrombosis                           |                                                                          |      1  4.0|
      Fat, Necrosis                        |                                                                   4      |      1  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +     +  +  +  +  +  +  +  +     +  +  +  +           +  +  +        +   |  31        |
      Gingival, Foreign Body               | X     X  X     X     X  X  X     X  X  X  X              X  X        X   |     27     |
      Gingival, Inflammation, Acute        | 1     1           1                                   1     1            |      9  1.0|
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           |          2  1  2     1  2        2  1  2  2              2               |     19  1.7|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                    1                     |      1  1.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Granuloma                            |                                                                          |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 6| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 8| 6| 9| 3| 2| 3| 3| 3| 2| 9| 3| 3| 3| 3| 3| 2| 2| 3| 2| 1| 3| 3| 3| 2|            |
                                           | 1| 3| 3| 4| 1| 9| 0| 0| 1| 9| 4| 0| 1| 1| 0| 1| 9| 9| 0| 9| 3| 1| 0| 1| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
          Cell                             | 1  2        1        1              1     1           1     1  1         |     22  1.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Mineralization                       |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Epithelium, Hyperplasia              |                                                             3            |      2  2.5|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                             3            |      2  2.5|
      Epithelium, Ulcer                    |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Ulcer                                |                               4                                          |      1  4.0|
      Epithelium, Erosion                  |                                                                          |      1  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                               4                                          |      1  4.0|
      Glands, Ectasia                      | 1                 1              2  1     2     1  1  1  1     1     1   |     17  1.1|

                                            __________________________________________________________________________|____________|
   Tooth                                   | +     +                                   +  +           +               |   6        |
      Malformation                         | X     X                                   X  X           X               |      6     |

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Inflammation, Chronic Active         |                                                    1                     |      2  2.0|
      Mineralization                       |                               1                                          |      2  1.5|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Degeneration, Fatty                  |                                                                          |      1  1.0|
      Hyperplasia                          |             1        3           3        2        2  2  1               |     14  2.1|
      Hypertrophy                          | 3           1  2  1        3     2  2  1           1  1  1           2  2|     26  1.7|
      Metaplasia, Osseous                  |                                                                          |      1  3.0|
      Capsule, Hyperplasia                 |    1  1  1  2  1  2  2  1  2  1  2  1  1  2  2  1  2     3  2  1  1  3  1|     41  1.5|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          | 2  2  2  2  2  2  2  2  2  3  2  3  3  2  2  2  2  2  2  2  3  2  2  2  3|     47  2.2|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  M  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  42        |
      Cyst                                 |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Pars Distalis, Cyst                  |                   2                                                      |      1  2.0|
      Pars Distalis, Hyperplasia           |                      2                                                   |      2  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 6| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 8| 6| 9| 3| 2| 3| 3| 3| 2| 9| 3| 3| 3| 3| 3| 2| 2| 3| 2| 1| 3| 3| 3| 2|            |
                                           | 1| 3| 3| 4| 1| 9| 0| 0| 1| 9| 4| 0| 1| 1| 0| 1| 9| 9| 0| 9| 3| 1| 0| 1| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Follicle, Cyst                       |                                                                          |      2  2.5|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                                          |      1  3.0|
      Granuloma Sperm                      |       3                                                                  |      2  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |          1  1                       1     2        1           1     1   |     17  1.1|
      Inflammation, Chronic Active         |                      3                                                   |      1  3.0|
      Mineralization                       |                                                          1               |      2  1.0|

                                            __________________________________________________________________________|____________|
   Penis                                   |                                                                          |   1        |
      Hemorrhage                           |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                                          |      1  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |    1        1     2  1     2  2  2  1        2              1  1  2  1   |     21  1.5|
      Inflammation, Chronic Active         |          2     1     1     3           2  2     4  2  3                  |     13  2.4|
      Duct, Cyst                           |       3     2                 2        2  2  2     2  2        3  3      |     18  2.4|

                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                                          |      1  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1           1  1  1     1        1     1  1  1     1  1        1  1  1   |     25  1.0|

                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Atrophy                              |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Mineralization                       |                                        1                                 |      2  1.5|
      Germinal Epithelium, Atrophy         |                                                                          |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                             +           +|   3        |

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  I  +  +  +  +  +  +|  46        |
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  M  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  46        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 6| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 8| 6| 9| 3| 2| 3| 3| 3| 2| 9| 3| 3| 3| 3| 3| 2| 2| 3| 2| 1| 3| 3| 3| 2|            |
                                           | 1| 3| 3| 4| 1| 9| 0| 0| 1| 9| 4| 0| 1| 1| 0| 1| 9| 9| 0| 9| 3| 1| 0| 1| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hemorrhage                           |                                                                          |      1  3.0|
      Hyperplasia, Lymphoid                |                                                                          |      1  3.0|
      Hyperplasia, Plasma Cell             |                                           3                              |      1  3.0|
      Inflammation, Granulomatous          |                                                    4                     |      1  4.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hematopoietic Cell Proliferation     |    2     4                             3  3           3     2           2|     12  2.8|
      Hyperplasia, Lymphoid                |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  M  M  +  +  +  +  +  +  +  +  +  +  M  M  +  +  +  +  +  +  +  +  +|  40        |
      Cyst                                 | 1  1           2        2           1           1  2        1  2  2  2   |     16  1.6|
      Ectopic Parathyroid Gland            |                                                    2              1      |      3  1.3|
      Ectopic Thyroid                      |                                                       2                  |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                             +            |   1        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |       2                                                                  |      2  2.0|
      Mineralization                       |                                           1                              |      3  1.0|
      Thrombosis                           |    1                                                                     |      3  2.3|
      Alveolar Epithelium, Hyperplasia     |       1                                                                  |      3  2.3|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |       1              3                                   3        2      |      4  2.3|
      Bronchiole, Foreign Body             |                                                                          |      1     |

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Foreign Body                         |          X                                X                              |      3     |
      Inflammation, Chronic Active         |                                           4                              |      2  3.0|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                               2                                          |      4  1.5|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 5| 6| 6| 7| 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 5| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 8| 6| 9| 3| 2| 3| 3| 3| 2| 9| 3| 3| 3| 3| 3| 2| 2| 3| 2| 1| 3| 3| 3| 2|            |
                                           | 1| 3| 3| 4| 1| 9| 0| 0| 1| 9| 4| 0| 1| 1| 0| 1| 9| 9| 0| 9| 3| 1| 0| 1| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      A     |
    0 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
      Cornea, Inflammation, Suppurative    |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                              +                           |   3        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  1.0|

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infarct                              |                                                                          |      2  2.5|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1        1  1  1  1  2  1  1     1  1  2  1  1     1  1        1  1  1   |     27  1.1|
      Inflammation, Chronic Active         |                                              1                           |      1  1.0|
      Metaplasia, Osseous                  |                                                       2                  |      2  2.5|
      Mineralization                       | 1  1  1     1  1  1  1  1  1  1  1  1     1  1  1  1  1  1  1  1  1  1  1|     43  1.0|
      Nephropathy                          | 2  2  1  1  2  2  1  2  2  1  1  1  2  2  1  1  2  2  2  2  1  1  1  2  1|     43  1.5|
      Cortex, Cyst                         |                      2           2     2                 1              3|     11  1.9|
      Renal Tubule, Hyperplasia            | 2                             2     2        2     2              2      |      9  2.0|
      Renal Tubule, Necrosis               |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1        1     1  1              1                                    |     12  1.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 2| 2| 3| 3| 3| 3| 3| 3| 2| 2| 2| 6| 2| 3| 2| 2| 2| 3| 3| 1| 3| 3|             
                                           | 1| 1| 9| 9| 9| 1| 0| 1| 1| 1| 1| 5| 9| 9| 3| 9| 0| 9| 9| 9| 1| 0| 4| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Periesophageal Tissue, Inflammation, |                                                                          |             
           Chronic Active                  |                                                                          |             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |          3                                               3               |             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                      2   |             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |          2                                                               |             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |             X                             X                              |             
      Clear Cell Focus                     |                      X        X                    X  X  X           X   |             
      Eosinophilic Focus                   |          X                             X                       X     X   |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |       1                       1        1        1     1              1   |             
      Inflammation, Chronic Active         |          1        1        1                       1        1           1|             
      Mixed Cell Focus                     |                   X  X                                               X  X|             
      Necrosis                             |                            2     3  2                             2      |             
      Hepatocyte, Vacuolization Cytoplasmic|                      2        1                       1  2              1|             

                                            __________________________________________________________________________|             
   Mesentery                               | +                                         +                              |             
      Fibrosis                             |                                           2                              |             
      Inflammation, Chronic Active         |                                                                          |             
      Mineralization                       |                                                                          |             
      Fat, Necrosis                        |                                           4                              |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             | +     +     +  +        +        +  +  +     +  +     +     +  +  +     +|             
      Gingival, Foreign Body               | X     X     X  X        X        X  X  X     X  X     X     X  X  X     X|             
      Gingival, Inflammation, Acute        |                                  1                    2                 1|             
      Gingival, Inflammation, Chronic      |                                                                   1      |             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           | 1     1     1  1        2           2  1     2  2           1  2         |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1  1  1     1  1  1     1  1  1  1     1  1  1  1     1  1     1  1|             
      Mineralization                       |                                                                   1      |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              | 2        2                                                               |             
      Epithelium, Inflammation, Chronic    |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 2| 2| 3| 3| 3| 3| 3| 3| 2| 2| 2| 6| 2| 3| 2| 2| 2| 3| 3| 1| 3| 3|             
                                           | 1| 1| 9| 9| 9| 1| 0| 1| 1| 1| 1| 5| 9| 9| 3| 9| 0| 9| 9| 9| 1| 0| 4| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
          Active                           |                                                                          |             
      Epithelium, Ulcer                    |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |          2                                                               |             
      Mineralization                       |                                                                          |             
      Epithelium, Hyperplasia              |                                                             2            |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |                                                                          |             
      Glands, Ectasia                      |    1  1  2                                               1               |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                          1               |             
      Artery, Inflammation, Chronic Active |                                                                2         |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |             2              2        1              1  2  2              2|             
      Hypertrophy                          |    1  2  2  2     2  2  3     1              3  2  1  3  2     1  2     2|             
      Inflammation, Suppurative            |                                                                          |             
      Capsule, Hyperplasia                 |    2  2  2  2  2  1     1  2  1  1  1  2  1  2  2  1     1  2  2  1     2|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2  2     2  2  2     2  2  2  3  2  2  2  2  2  2  3  3  2     2     2  3|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  M  +  +  +  +  +  +  +  +  M  +  +  +  +  +  M  +  M  +  +  +  M  +  M|             
      Cyst                                 |                                                                          |             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                                                          |             
      Pars Distalis, Hyperplasia           |                            2                                             |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicle, Cyst                       |          2                                                               |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1     1        1  1  1     1              1  1  2  1     1  1  1     1|             
      Inflammation, Chronic Active         |                         2                                                |             

                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  2  2  2  1     2  1  2           1     2  1        2  1        1   |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 2| 2| 3| 3| 3| 3| 3| 3| 2| 2| 2| 6| 2| 3| 2| 2| 2| 3| 3| 1| 3| 3|             
                                           | 1| 1| 9| 9| 9| 1| 0| 1| 1| 1| 1| 5| 9| 9| 3| 9| 0| 9| 9| 9| 1| 0| 4| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Inflammation, Chronic Active         | 3                                            2     2           2         |             
      Duct, Cyst                           |    2     2     2  3           2     2                 2  2  2            |             

                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1     1  1     1     1     1  1     1     1  2           1        1  1|             
      Artery, Inflammation, Chronic Active |                                                                2         |             

                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Dilatation                           |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1                                                                     |             

                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                         2                                                |             
      Mineralization                       |                                                                          |             
      Germinal Epithelium, Atrophy         |                         2                          2                     |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Lymph Node                              |       +                                                                  |             
      Inguinal, Hyperplasia, Plasma Cell   |                                                                          |             
      Lumbar, Hyperplasia, Plasma Cell     |                                                                          |             
      Mediastinal, Hyperplasia, Plasma Cell|                                                                          |             
      Pancreatic, Hyperplasia, Lymphoid    |                                                                          |             
      Renal, Hyperplasia, Plasma Cell      |                                                                          |             
      Renal, Inflammation, Suppurative     |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  M  +  M  +  M  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |                                                                          |             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     | 3     2                          3  4     2                    2  2      |             
      Hyperplasia, Lymphoid                |                               3                                          |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  M  +  +|             
      Cyst                                 | 2  2     2     2                 1              2              2         |             
      Ectopic Parathyroid Gland            |                         2                                                |             
      Mineralization                       |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                                                                          |             
      Epidermis, Hyperplasia               |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 2| 2| 3| 3| 3| 3| 3| 3| 2| 2| 2| 6| 2| 3| 2| 2| 2| 3| 3| 1| 3| 3|             
                                           | 1| 1| 9| 9| 9| 1| 0| 1| 1| 1| 1| 5| 9| 9| 3| 9| 0| 9| 9| 9| 1| 0| 4| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
      Epidermis, Ulcer                     |                                                                          |             
      Subcutaneous Tissue, Fibrosis        |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                              2                           |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             
      Inflammation, Chronic                |                            1                                             |             
      Inflammation, Chronic Active         |                                           2                              |             
      Mineralization                       |                                                                      1   |             
      Thrombosis                           |                                              2                           |             
      Alveolar Epithelium, Hyperplasia     |                         2              2           2                     |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                                           3        2              2     3|             
      Mediastinum, Inflammation,           |                                                                          |             
          Suppurative                      |                                                                   2      |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |             X                                                     X      |             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     |                                        +                                 |             
      Cornea, Inflammation, Chronic Active |                                        2                                 |             
      Cornea, Metaplasia, Squamous         |                                        4                                 |             

                                            __________________________________________________________________________|             
   Harderian Gland                         |                            +           +                                 |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infarct                              |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1     1  1  1  2  1  1  1  3        1        1  1  1  1  1  1     1   |             
      Metaplasia, Osseous                  |                                                                          |             
      Mineralization                       | 1  1  1  1  1  1  1  1  1  1  1  1     1  1  1  1  1  1  1  1  1  1  1  1|             
      Nephropathy                          | 2  1  1  1  2  2  2  2  1  2  2  2  1  2  1  2  2  2  2  1  1  2     2  2|             
      Artery, Inflammation, Chronic Active |                                                                3         |             
      Cortex, Cyst                         |                      2        3        2        2                        |             
      Renal Tubule, Hyperplasia            |                      2        2                    2                     |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 6| 7| 5| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 2| 2| 3| 3| 3| 3| 3| 3| 2| 2| 2| 6| 2| 3| 2| 2| 2| 3| 3| 1| 3| 3|             
                                           | 1| 1| 9| 9| 9| 1| 0| 1| 1| 1| 1| 5| 9| 9| 3| 9| 0| 9| 9| 9| 1| 0| 4| 0| 0|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
    1.5                                    | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
    MG/KG                                  | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |          1        1  1           1     1                                 |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 2| 3| 2| 3| 3| 2| 2| 2| 2| 3| 2| 0| 2| 3| 3|            |
                                           | 0| 0| 0| 0| 0| 4| 1| 1| 0| 0| 9| 0| 9| 1| 0| 9| 9| 9| 5| 0| 9| 5| 9| 0| 0|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Periesophageal Tissue, Inflammation, |                                                                          |            |
           Chronic Active                  |                2                                                         |      1  2.0|

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia                          |             3                                                            |      3  3.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     | X                                            X                           |      4     |
      Clear Cell Focus                     |          X  X                          X     X                           |     10     |
      Eosinophilic Focus                   |       X  X        X        X        X                             X      |     10     |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |             1        1        1     1                       1            |     11  1.0|
      Inflammation, Chronic Active         |    1     2  1              1  1     1  1  2  1  1  1  1  1  1           1|     21  1.1|
      Mixed Cell Focus                     |                   X     X  X     X     X     X                    X      |     11     |
      Necrosis                             |                         2                                                |      5  2.2|
      Hepatocyte, Vacuolization Cytoplasmic|       2  2                       2           2  1                        |     10  1.6|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                +                                      +        +  +      |   6        |
      Fibrosis                             |                                                                          |      1  2.0|
      Inflammation, Chronic Active         |                                                                   2      |      1  2.0|
      Mineralization                       |                                                                   2      |      1  2.0|
      Fat, Necrosis                        |                                                                3         |      2  3.5|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +  +        +  +     +  +  +        +     +  +     +     +  +  +        +|  30        |
      Gingival, Foreign Body               | X  X           X     X  X  X        X     X  X     X     X  X  X        X|     29     |
      Gingival, Inflammation, Acute        |                                                                          |      3  1.3|
      Gingival, Inflammation, Chronic      |                                                                          |      1  1.0|
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           | 2  2        2  2     2  2  2        2     2  2     2     2  2  2        3|     26  1.8|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                             2            |      1  2.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 2| 3| 2| 3| 3| 2| 2| 2| 2| 3| 2| 0| 2| 3| 3|            |
                                           | 0| 0| 0| 0| 0| 4| 1| 1| 0| 0| 9| 0| 9| 1| 0| 9| 9| 9| 5| 0| 9| 5| 9| 0| 0|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
          Cell                             | 1  1  1        1  1  1     1     1        1  1  1  1           1  1  1   |     35  1.0|
      Mineralization                       |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |                2                                                         |      3  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                       2                  |      1  2.0|
      Epithelium, Ulcer                    |                                                       4                  |      1  4.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  2.0|
      Mineralization                       |                                                                   1      |      1  1.0|
      Epithelium, Hyperplasia              |                                                                          |      1  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                             2            |      1  2.0|
      Glands, Ectasia                      |    1                 1     1  1           1                       1      |     10  1.1|

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  1.0|
      Artery, Inflammation, Chronic Active |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                      2           1     1  2                             1|     12  1.6|
      Hypertrophy                          |    2  2  1  2  3  1     2  3     2  2  3     2  2        1  2     1  1  1|     34  1.9|
      Inflammation, Suppurative            |                                                             1            |      1  1.0|
      Capsule, Hyperplasia                 | 2  1  1  2        1  1  1  2  1     1  2  1  2     2  1  1  1  1  2  2   |     41  1.5|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2  2  2  2  2  2  2  2  2  2  2  2  2  2  2  3  2  2  2     3  2        2|     43  2.1|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  M  +  +  M  +  M  M  +  +  M  +  +  M  +  +  +  +  M  +  +  M  +  +|  35        |
      Cyst                                 |                                                 2                    2   |      2  2.0|

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Cyst                  |       2                                                           2      |      2  2.0|
      Pars Distalis, Hyperplasia           |                                        2                                 |      2  2.0|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicle, Cyst                       |       2                                                                  |      2  2.0|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        


                                                             Page  53                                                               
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 2| 3| 2| 3| 3| 2| 2| 2| 2| 3| 2| 0| 2| 3| 3|            |
                                           | 0| 0| 0| 0| 0| 4| 1| 1| 0| 0| 9| 0| 9| 1| 0| 9| 9| 9| 5| 0| 9| 5| 9| 0| 0|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1     1     2     1        1  1  1  1  1  2                       1      |     26  1.1|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 2  1     2        1  1  3              1  1                    1     1  1|     25  1.4|
      Inflammation, Chronic Active         |                               3  2                                       |      6  2.3|
      Duct, Cyst                           |          2     2  2  3        2        3  2  3              2  2     3   |     20  2.3|

                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  1  2  1              1  1  1  1  1     1  1     1        1  1  1|     31  1.1|
      Artery, Inflammation, Chronic Active |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Dilatation                           |                                                       4                  |      1  4.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                1                                                         |      2  1.0|

                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
      Mineralization                       |                                           1                       1      |      2  1.0|
      Germinal Epithelium, Atrophy         |                                                                          |      2  2.0|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Lymph Node                              | +              +                                      +     +            |   5        |
      Inguinal, Hyperplasia, Plasma Cell   |                                                             2            |      1  2.0|
      Lumbar, Hyperplasia, Plasma Cell     |                                                             3            |      1  3.0|
      Mediastinal, Hyperplasia, Plasma Cell|                                                             2            |      1  2.0|
      Pancreatic, Hyperplasia, Lymphoid    | 4                                                                        |      1  4.0|
      Renal, Hyperplasia, Plasma Cell      |                                                             4            |      1  4.0|
      Renal, Inflammation, Suppurative     |                                                             1            |      1  1.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Hyperplasia, Lymphoid                |                                        4                                 |      1  4.0|
      Hyperplasia, Plasma Cell             |                                                             4            |      1  4.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  M  +  +  +|  43        |
      Hyperplasia, Lymphoid                |                                              4                           |      1  4.0|
      Hyperplasia, Plasma Cell             |                                                             4            |      1  4.0|
      Inflammation, Suppurative            |                                                             2            |      1  2.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 2| 3| 2| 3| 3| 2| 2| 2| 2| 3| 2| 0| 2| 3| 3|            |
                                           | 0| 0| 0| 0| 0| 4| 1| 1| 0| 0| 9| 0| 9| 1| 0| 9| 9| 9| 5| 0| 9| 5| 9| 0| 0|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hematopoietic Cell Proliferation     |    2           2              3           3           2     3            |     13  2.5|
      Hyperplasia, Lymphoid                | 3                    4                                      3            |      4  3.3|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  48        |
      Cyst                                 |    2  2  2           1  2  2     2     2        1              1  2     2|     19  1.8|
      Ectopic Parathyroid Gland            |                                                                          |      1  2.0|
      Mineralization                       |                                                 1                        |      1  1.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                           1                 4            |      2  2.5|
      Epidermis, Hyperplasia               |                                           3                 4            |      2  3.5|
      Epidermis, Ulcer                     |                                           1                 4            |      2  2.5|
      Subcutaneous Tissue, Fibrosis        |                                           4                              |      1  4.0|

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                               2                                          |      1  2.0|
      Inflammation, Chronic                |                                                                          |      1  1.0|
      Inflammation, Chronic Active         |                                                             3            |      2  2.5|
      Mineralization                       |                                                                          |      1  1.0|
      Thrombosis                           |                                                                1         |      2  1.5|
      Alveolar Epithelium, Hyperplasia     | 2                 2              2                                       |      6  2.0|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |          2                    2                             3           2|      8  2.4|
      Mediastinum, Inflammation,           |                                                                          |            |
          Suppurative                      |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |                                                             X            |      3     |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 6| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7|            |
                             DAY ON TEST   | 3| 3| 3| 3| 3| 4| 3| 3| 3| 3| 2| 3| 2| 3| 3| 2| 2| 2| 2| 3| 2| 0| 2| 3| 3|            |
                                           | 0| 0| 0| 0| 0| 4| 1| 1| 0| 0| 9| 0| 9| 1| 0| 9| 9| 9| 5| 0| 9| 5| 9| 0| 0|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|      A     |
    1.5                                    | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
    MG/KG                                  | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 SPECIAL SENSES SYSTEM - cont              |                                                                          |            |
                                           |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |
      Cornea, Inflammation, Chronic Active |                                                                          |      1  2.0|
      Cornea, Metaplasia, Squamous         |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   2        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infarct                              |                                                             4           3|      2  3.5|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1  1  1  1  1     1     2  1  1     1  1  1  1     1  2     1     1|     37  1.1|
      Metaplasia, Osseous                  |                                              2                           |      1  2.0|
      Mineralization                       | 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1|     49  1.0|
      Nephropathy                          | 2  2  2  2  2     2  2  2  2  1  2  2  2  2  2  2  2  1  1  2  2  1  2  2|     48  1.8|
      Artery, Inflammation, Chronic Active |                                                                          |      1  3.0|
      Cortex, Cyst                         |       2                    2        2     2  2  2           2  1         |     12  2.0|
      Renal Tubule, Hyperplasia            |                      2     2     2     2     2                           |      8  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1     1  1     1           1  1  1        1  1     1        1           1|     17  1.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 2| 2| 5| 3| 3| 2| 2| 3| 3| 3| 3| 3| 3| 2| 3| 3| 2| 3| 2|             
                                           | 0| 1| 9| 1| 1| 0| 9| 9| 5| 9| 0| 9| 9| 1| 0| 1| 0| 1| 1| 9| 1| 0| 9| 1| 9|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Ectasia                              |                                                                          |             
      Hyperplasia                          |                                                             3            |             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia, Lymphoid |                   2                                                      |             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Angiectasis                          |                                           2                              |             
      Basophilic Focus                     |                   X                          X  X                        |             
      Clear Cell Focus                     |             X        X                 X              X     X        X   |             
      Eosinophilic Focus                   | X        X                                      X  X  X     X        X   |             
      Fibrosis                             |                                                                          |             
      Hematopoietic Cell Proliferation     |                            2                                         1   |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                    1  1        1         |             
      Inflammation, Chronic Active         |    1           3  1  1  2                 1  1     1  1  1              1|             
      Inflammation, Granulomatous          |          3                                                               |             
      Mineralization                       |                                                                          |             
      Mixed Cell Focus                     | X                             X  X                             X     X   |             
      Necrosis                             |                         2                                                |             
      Pigmentation                         |                                                                          |             
      Tension Lipidosis                    |                               X                                          |             
      Bile Duct, Cyst                      |                                              3                           |             
      Hepatocyte, Vacuolization Cytoplasmic|                   1                 1  1                             2   |             
      Hepatocyte, Portal, Hypertrophy      |                                                                          |             
      Hepatocyte, Centrilobular,           |                                                                          |             
          Degeneration                     |                                                                          |             

                                            __________________________________________________________________________|             
   Mesentery                               | +  +     +     +                                      +                  |             
      Inflammation, Chronic Active         |                3                                                         |             
      Inflammation, Granulomatous          |    3     3                                                               |             
      Mineralization                       | 1                                                                        |             
      Fat, Necrosis                        | 4                                                                        |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |    +  +        +     +  +     +                    +  +        +        +|             
      Gingival, Foreign Body               |    X  X        X        X     X                    X  X        X        X|             
      Gingival, Inflammation, Acute        |    1  1                       1                    2                    1|             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |                1     2  1                             2        1         |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 2| 2| 5| 3| 3| 2| 2| 3| 3| 3| 3| 3| 3| 2| 3| 3| 2| 3| 2|             
                                           | 0| 1| 9| 1| 1| 0| 9| 9| 5| 9| 0| 9| 9| 1| 0| 1| 0| 1| 1| 9| 1| 0| 9| 1| 9|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1  1     1  1  1     1  1  2  1     1  1  1  1  1  1        1      |             
      Inflammation, Chronic Active         |                            4                                             |             
      Mineralization                       |                                                             1            |             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst, Squamous                       |                                                                          |             
      Epithelium, Hyperplasia              |                                                             3            |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |          2                                                  2            |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |          2                                                               |             
      Epithelium, Inflammation, Chronic    |                                                                          |             
          Active                           |          2                                                               |             
      Glands, Ectasia                      | 1                    1           1     1              1  1  1  1  1  1   |             
      Serosa, Inflammation, Granulomatous  |          3                                                               |             

                                            __________________________________________________________________________|             
   Tooth                                   |                                                                          |             
      Malformation                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                            1                                             |             
      Hyperplasia                          | 1     2  2  1     2           2  2                 2        2            |             
      Hypertrophy                          | 1  2        1        2        2  1  2     2        1  2  2  1        2   |             
      Capsule, Hyperplasia                 | 1  2  1  1  2  2  2  1  1     1  1     1  2  2  1  1  2  1  1  1  2  1  1|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                            1                                             |             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 2  2  2  2  2  3  2  2  2  2  2  2  2  2  2  2  2  2  3  2  2  2  2  2   |             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 |                                                             2            |             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Pars Distalis, Cyst                  |                                           1        2                     |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Follicle, Cyst                       |             3                 2                                          |             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 2| 2| 5| 3| 3| 2| 2| 3| 3| 3| 3| 3| 3| 2| 3| 3| 2| 3| 2|             
                                           | 0| 1| 9| 1| 1| 0| 9| 9| 5| 9| 0| 9| 9| 1| 0| 1| 0| 1| 1| 9| 1| 0| 9| 1| 9|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                          |             
      Inflammation, Suppurative            |                                                                          |             

                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Granuloma Sperm                      |                                                       2                  |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1           1  1  1  1  1     1  1  1     1  1  1  1     1  1     1      |             
      Mineralization                       |                                                                          |             

                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  1  1  2  1  2        1  1     2  2        1  2  1     2        1   |             
      Inflammation, Chronic Active         | 3                                            3           2     2        2|             
      Duct, Cyst                           |          2  2  2        3        3              2     2  2              2|             

                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1        1  1  1  1  1     1  1  1  1  1  1  1  1        1        1  1  1|             
      Inflammation, Suppurative            |                                                                          |             

                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                                                                          |             

                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atrophy                              |                                                                          |             
      Mineralization                       |                                                                          |             
      Germinal Epithelium, Atrophy         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |                3           4                                             |             

                                            __________________________________________________________________________|             
   Lymph Node                              |          +                                            +                  |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Plasma Cell             |                                                                          |             
      Infiltration Cellular,               |                                                                          |             
          Polymorphonuclear                |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia, Lymphoid                |          3                                                               |             
      Inflammation, Chronic Active         |          2                                                               |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     | 2     2        2  2     3  4                                   2         |             
      Hyperplasia, Lymphoid                |                                                                          |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atypia Cellular                      |                                                                          |             
      Cyst                                 | 2           2        2        2                                2         |             
      Ectopic Parathyroid Gland            |                                                                          |             
      Thymocyte, Necrosis                  |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 2| 2| 5| 3| 3| 2| 2| 3| 3| 3| 3| 3| 3| 2| 3| 3| 2| 3| 2|             
                                           | 0| 1| 9| 1| 1| 0| 9| 9| 5| 9| 0| 9| 9| 1| 0| 1| 0| 1| 1| 9| 1| 0| 9| 1| 9|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                            1                                             |             
      Inflammation, Chronic Active         |                            4                    4     1                  |             
      Epidermis, Hyperkeratosis            |                                                       2                  |             
      Epidermis, Hyperplasia               |                                                 3     3                  |             
      Epidermis, Ulcer                     |                            4                    4                        |             
      Epidermis, Pinna, Hyperplasia        |                                                       3                  |             
      Epidermis, Pinna, Ulcer              |                                                       4                  |             
      Pinna, Inflammation, Chronic Active  |                                                       2                  |             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |          2                                                               |             
      Thrombosis                           | 2                                                                        |             
      Alveolar Epithelium, Hyperplasia     |                                                                      2   |             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                         2                          2                     |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                X              X                                          |             
      Inflammation, Chronic Active         |                1                                                         |             
      Nasolacrimal Duct, Inflammation,     |                                                                          |             
           Suppurative                     |                                                                          |             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Harderian Gland                         | +              +     +                          +                        |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infarct                              |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1        1  3  1  1  1     1  1  1     1  1     1  1  1  1  1  1  1  1|             
      Inflammation, Chronic Active         |                            2                                             |             
      Inflammation, Suppurative            |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 4| 7| 7| 7| 7| 7| 6| 4| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 3| 2| 3| 3| 3| 2| 2| 5| 3| 3| 2| 2| 3| 3| 3| 3| 3| 3| 2| 3| 3| 2| 3| 2|             
                                           | 0| 1| 9| 1| 1| 0| 9| 9| 5| 9| 0| 9| 9| 1| 0| 1| 0| 1| 1| 9| 1| 0| 9| 1| 9|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    3 MG/KG                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2| 2| 2| 2| 2| 2|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
      Mineralization                       | 1  1     1  1     1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1|             
      Nephropathy                          | 1  2  2     1  3  1  2  1  2  1  1  2  1  1  1  2  2  1  1  2  1  1  1  1|             
      Cortex, Cyst                         |                                                                          |             
      Renal Tubule, Hyperplasia            |    2     2        2           2        2  2                              |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hemorrhage                           |                                                                          |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1  1                    1                                             |             
      Inflammation, Suppurative            |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 2| 3| 2| 2| 3| 3| 2| 3| 2| 1| 3| 3| 9| 2| 3| 2| 3| 0| 2| 2| 3| 3| 0|            |
                                           | 9| 9| 9| 1| 9| 9| 0| 1| 9| 0| 9| 2| 0| 0| 4| 9| 1| 9| 1| 2| 9| 9| 1| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Ectasia                              |                                                 2                        |      1  2.0|
      Hyperplasia                          |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Peyer's Patch, Hyperplasia, Lymphoid |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Angiectasis                          |                                                                          |      1  2.0|
      Basophilic Focus                     |             X           X                                   X            |      6     |
      Clear Cell Focus                     |                                        X           X  X     X            |     10     |
      Eosinophilic Focus                   | X  X                    X     X                                   X      |     12     |
      Fibrosis                             |                                  2                                       |      1  2.0|
      Hematopoietic Cell Proliferation     |                                                                1         |      3  1.3|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |    1  1                                      1  1                        |      7  1.0|
      Inflammation, Chronic Active         |    1  1        1     1  1        1     2        1                        |     19  1.2|
      Inflammation, Granulomatous          |                                                                          |      1  3.0|
      Mineralization                       |                                  2                                       |      1  2.0|
      Mixed Cell Focus                     |                X                       X        X  X     X        X      |     11     |
      Necrosis                             |                                                                          |      1  2.0|
      Pigmentation                         |                            2     1                                       |      2  1.5|
      Tension Lipidosis                    |                                                                          |      1     |
      Bile Duct, Cyst                      |                                                                          |      1  3.0|
      Hepatocyte, Vacuolization Cytoplasmic|             2  1     2                 2                    2            |      9  1.6|
      Hepatocyte, Portal, Hypertrophy      |                            3                                             |      1  3.0|
      Hepatocyte, Centrilobular,           |                                                                          |            |
          Degeneration                     |                            3                                             |      1  3.0|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                                  +                                       |   6        |
      Inflammation, Chronic Active         |                                                                          |      1  3.0|
      Inflammation, Granulomatous          |                                                                          |      2  3.0|
      Mineralization                       |                                                                          |      1  1.0|
      Fat, Necrosis                        |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +  +  +  +     +  +     +  +  +  +        +  +     +     +     +     +  +|  27        |
      Gingival, Foreign Body               | X  X  X  X     X  X     X  X  X  X        X  X     X     X     X     X  X|     26     |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 2| 3| 2| 2| 3| 3| 2| 3| 2| 1| 3| 3| 9| 2| 3| 2| 3| 0| 2| 2| 3| 3| 0|            |
                                           | 9| 9| 9| 1| 9| 9| 0| 1| 9| 0| 9| 2| 0| 0| 4| 9| 1| 9| 1| 2| 9| 9| 1| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Gingival, Inflammation, Acute        | 1                 1           1  1                             2         |     10  1.2|
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           |    2  2  1              2  2              2  1     1     2           2  2|     16  1.6|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1        1  1  1        1     1  1  1  1  1  1  1  1  1  1  1  1     1   |     36  1.0|
      Inflammation, Chronic Active         |                                                                          |      1  4.0|
      Mineralization                       |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Cyst, Squamous                       |                         3                                                |      1  3.0|
      Epithelium, Hyperplasia              |                                                                          |      1  3.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                                          |      2  2.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Epithelium, Hyperplasia              |                                                                          |      1  2.0|
      Epithelium, Inflammation, Chronic    |                                                                          |            |
          Active                           |                                                                          |      1  2.0|
      Glands, Ectasia                      |       1        1        2              1  1  1  1  1        1     1      |     20  1.1|
      Serosa, Inflammation, Granulomatous  |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Tooth                                   |          +                                                               |   1        |
      Malformation                         |          X                                                               |      1     |

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |                1                                                         |      1  1.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|
      Hyperplasia                          |                   1           2  1  2  2     2        2                  |     16  1.8|
      Hypertrophy                          | 1  2           2     2  1  1           2     2  2  1  2     1     2  2  1|     28  1.6|
      Capsule, Hyperplasia                 |    2     1  2  2  1  2  2     1  1     1        1  2     1  3     2  2  1|     40  1.5|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2  2  2  2  2  2  2  2  3  2  2  2  2  2  2  2  2  2  2  2  2  2     2  2|     48  2.1|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | +  M  M  M  +  M  +  +  +  M  M  +  +  +  +  +  M  +  M  +  +  +  +  M  +|  39        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 2| 3| 2| 2| 3| 3| 2| 3| 2| 1| 3| 3| 9| 2| 3| 2| 3| 0| 2| 2| 3| 3| 0|            |
                                           | 9| 9| 9| 1| 9| 9| 0| 1| 9| 0| 9| 2| 0| 0| 4| 9| 1| 9| 1| 2| 9| 9| 1| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |                                                                          |            |
      Cyst                                 |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  I  +  +  +  +  +  +  +  +|  49        |
      Pars Distalis, Cyst                  |                         2                 2  1                           |      5  1.6|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Follicle, Cyst                       |                                                                          |      2  2.5|

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                                         +|   1        |
      Inflammation, Suppurative            |                                                                         3|      1  3.0|

                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Granuloma Sperm                      |                                                                          |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |       1  1  1     1  1  1     1     1  1     1  1     1  1        1      |     30  1.0|
      Mineralization                       |                1                                                         |      1  1.0|

                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |          1        1     2           1           1     1  1  2  1  2  2  2|     27  1.4|
      Inflammation, Chronic Active         |       4                             1                                    |      7  2.4|
      Duct, Cyst                           |          3              2           2     2     2  2  2           3  2   |     18  2.2|

                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1     1  1  1  1     1  1           1     1  1     1  1  1  1     1  1   |     34  1.0|
      Inflammation, Suppurative            |                                                                         3|      1  3.0|

                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1                       1                                                |      2  1.0|

                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Atrophy                              |                4                                                         |      1  4.0|
      Mineralization                       |                                              1                           |      1  1.0|
      Germinal Epithelium, Atrophy         |                            3                 2                           |      2  2.5|

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                          4     4         |      4  3.8|

                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                  +                                       |   3        |

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 2| 3| 2| 2| 3| 3| 2| 3| 2| 1| 3| 3| 9| 2| 3| 2| 3| 0| 2| 2| 3| 3| 0|            |
                                           | 9| 9| 9| 1| 9| 9| 0| 1| 9| 0| 9| 2| 0| 0| 4| 9| 1| 9| 1| 2| 9| 9| 1| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |                                                                          |            |
      Hyperplasia, Plasma Cell             |                            3                                             |      1  3.0|
      Infiltration Cellular,               |                                                                          |            |
          Polymorphonuclear                |                            3                                             |      1  3.0|

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Hyperplasia, Lymphoid                |                                                                          |      1  3.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |       2              2     3     3        2              2     3         |     14  2.4|
      Hyperplasia, Lymphoid                |    3                                                                     |      1  3.0|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  M  +  +  +  +  M  +  +  +|  46        |
      Atypia Cellular                      |             1                                                            |      1  1.0|
      Cyst                                 |          1  1  2     2  2     1  1  2  2                 1  2        2  2|     18  1.7|
      Ectopic Parathyroid Gland            |             2              2                          1                  |      3  1.7|
      Thymocyte, Necrosis                  |                                                                         2|      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|            |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  1.0|
      Inflammation, Chronic Active         |                                                                          |      3  3.0|
      Epidermis, Hyperkeratosis            |                                                                          |      1  2.0|
      Epidermis, Hyperplasia               |                                                                          |      2  3.0|
      Epidermis, Ulcer                     |                                                                          |      2  4.0|
      Epidermis, Pinna, Hyperplasia        |                                                                          |      1  3.0|
      Epidermis, Pinna, Ulcer              |                                                                          |      1  4.0|
      Pinna, Inflammation, Chronic Active  |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                  +                             +         |   2        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                          |      1  2.0|
      Thrombosis                           |                                                                          |      1  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 6| 7| 7| 6| 7| 7| 7| 7| 5| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 2| 2| 2| 3| 2| 2| 3| 3| 2| 3| 2| 1| 3| 3| 9| 2| 3| 2| 3| 0| 2| 2| 3| 3| 0|            |
                                           | 9| 9| 9| 1| 9| 9| 0| 1| 9| 0| 9| 2| 0| 0| 4| 9| 1| 9| 1| 2| 9| 9| 1| 1| 3|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|      A     |
    3 MG/KG                                | 2| 2| 2| 2| 3| 3| 3| 3| 3| 3| 3| 3| 3| 3| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
      Alveolar Epithelium, Hyperplasia     | 3  2        2                                               2            |      5  2.2|
      Alveolus, Infiltration Cellular,     |                                                                          |            |
           Histiocyte                      |                                  2                                       |      3  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         |                            X              X                              |      4     |
      Inflammation, Chronic Active         |                            4              2                              |      3  2.3|
      Nasolacrimal Duct, Inflammation,     |                                                                          |            |
           Suppurative                     |                            4                                             |      1  4.0|

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |             +                                            +     +         |   7        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infarct                              |                                                             2            |      1  2.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1     1  1  1  1  1  1  1  1  1     1  1        1  1  1     1  1  1  1   |     39  1.1|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
      Inflammation, Suppurative            |                                                                         1|      1  1.0|
      Mineralization                       | 1  1  1  1  1  1  1  1  1     1  1  1  1  1  1  1  1  1  1  1  1  1  1  1|     47  1.0|
      Nephropathy                          | 1  1  1  1  1  1  1  1  1     1  1  1  2     1  2  1  1  2  1  1  2  2  1|     47  1.3|
      Cortex, Cyst                         | 3           2  1     2                    1     2           2        2   |      8  1.9|
      Renal Tubule, Hyperplasia            |                         2              2                    2            |      9  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hemorrhage                           |                                                                         3|      1  3.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                   1              1                 1        1     1  1   |      9  1.0|
      Inflammation, Suppurative            |                                                                         2|      1  2.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 0| 6| 7| 7| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 2| 3| 3| 3| 3| 3| 2| 3| 3| 0| 2| 3| 3| 8| 8| 8| 8| 8| 8| 8| 3| 3| 2| 3|             
                                           | 0| 9| 0| 0| 0| 0| 0| 9| 1| 0| 3| 1| 1| 0| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM                         |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                               4                                          |             

                                            __________________________________________________________________________|             
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |       3                                                                  |             

                                            __________________________________________________________________________|             
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Peyer's Patch, Hyperplasia, Lymphoid |                2                                                         |             

                                            __________________________________________________________________________|             
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Basophilic Focus                     |                         X                                                |             
      Clear Cell Focus                     |                            X           X        X                        |             
      Eosinophilic Focus                   |                                                                         X|             
      Hematopoietic Cell Proliferation     |             1                                                            |             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1        1  1        1                                      1         |             
      Inflammation, Chronic Active         | 1     1     1     1  1           2  1  1        1  1  1     1            |             
      Mixed Cell Focus                     |                                        X                                 |             
      Pigmentation                         |                         1                                      1         |             
      Bile Duct, Cyst                      |                                                                3         |             
      Bile Duct, Hyperplasia               |                                  3                                       |             
      Hepatocyte, Vacuolization Cytoplasmic|                            2              1  1  1  2     2  2           1|             

                                            __________________________________________________________________________|             
   Mesentery                               |                                                       +                  |             
      Inflammation, Chronic Active         |                                                       2                  |             

                                            __________________________________________________________________________|             
   Oral Mucosa                             |          +  +                       +                             +      |             
      Gingival, Foreign Body               |          X  X                       X                             X      |             
      Gingival, Inflammation, Acute        |             1                                                     2      |             
      Gingival, Inflammation, Chronic      |                                                                          |             
          Active                           |                                     2                                    |             

                                            __________________________________________________________________________|             
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |                         2                                                |             
      Artery, Mineralization               |                         2                                                |             

                                            __________________________________________________________________________|             
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1  1  1  1  1     1           1  1  1  1           1     1  1     1|             

                                            __________________________________________________________________________|             
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Epithelium, Hyperplasia              |                                                                          |             

                                            __________________________________________________________________________|             
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Mineralization                       |                                                                          |             
      Glands, Ectasia                      |    1     1        1  2                                                   |             

                                            __________________________________________________________________________|             
   Tooth                                   |    +              +                                                      |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 0| 6| 7| 7| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 2| 3| 3| 3| 3| 3| 2| 3| 3| 0| 2| 3| 3| 8| 8| 8| 8| 8| 8| 8| 3| 3| 2| 3|             
                                           | 0| 9| 0| 0| 0| 0| 0| 9| 1| 0| 3| 1| 1| 0| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 ALIMENTARY SYSTEM - cont                  |                                                                          |             
                                           |                                                                          |             
      Malformation                         |    X              X                                                      |             

 _____________________________________________________________________________________________________________________|             
 CARDIOVASCULAR SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                         2                                                |             
      Mineralization                       |                         2                                                |             

 _____________________________________________________________________________________________________________________|             
 ENDOCRINE SYSTEM                          |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          | 1        2           3     1                 1                          1|             
      Hypertrophy                          | 1           1     2  2              2  2        2           1  2        1|             
      Capsule, Hyperplasia                 | 2  2  1  2  2  1  1  1  1  1     1  2  3  1  1  1  1  1  1  1  2  2  1  2|             

                                            __________________________________________________________________________|             
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hyperplasia                          |    2  2  2  2  2  3  2  3  2     2  2  2  2  2  2  2  2  2  2  2  2  2  3|             

                                            __________________________________________________________________________|             
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +  M  +  +  +  M  M  M  M  +  +  +  +  +  +  +|             
      Cyst                                 |                                                                          |             

                                            __________________________________________________________________________|             
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Atypia Cellular                      |                                        2                                 |             
      Pars Distalis, Cyst                  |    1                 2                                         1         |             

                                            __________________________________________________________________________|             
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 GENERAL BODY SYSTEM                       |                                                                          |             
                                           |                                                                          |             
    None                                   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 GENITAL SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Coagulating Gland                       |                                                                          |             

                                            __________________________________________________________________________|             
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |          1        1  1     1        1  1  1  1  1     1        1     1  1|             
      Inflammation, Chronic Active         |                         2                                                |             

                                            __________________________________________________________________________|             
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1  1  2                 1        1  2     2     1  1  1     2  1     1|             
      Inflammation, Chronic Active         |                                                          2               |             
      Duct, Cyst                           | 2     2        2        3  3        3                    2     2  2     2|             

                                            __________________________________________________________________________|             
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             | 1  1        1  1  1  1  1  1        1  1  1     1  1     1  1  1        1|             

                                            __________________________________________________________________________|             
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM                      |                                                                          |             
                                           |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 0| 6| 7| 7| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 2| 3| 3| 3| 3| 3| 2| 3| 3| 0| 2| 3| 3| 8| 8| 8| 8| 8| 8| 8| 3| 3| 2| 3|             
                                           | 0| 9| 0| 0| 0| 0| 0| 9| 1| 0| 3| 1| 1| 0| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Lymph Node                              |                                                                          |             

                                            __________________________________________________________________________|             
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                         3                                                |             

                                            __________________________________________________________________________|             
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Hematopoietic Cell Proliferation     |                                                                          |             

                                            __________________________________________________________________________|             
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Cyst                                 | 1  2  2           1                    2     1                 2         |             
      Ectopic Parathyroid Gland            |                                        1                                 |             

 _____________________________________________________________________________________________________________________|             
 INTEGUMENTARY SYSTEM                      |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M  M|             

                                            __________________________________________________________________________|             
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 MUSCULOSKELETAL SYSTEM                    |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

                                            __________________________________________________________________________|             
   Skeletal Muscle                         |                                                                          |             

 _____________________________________________________________________________________________________________________|             
 NERVOUS SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 RESPIRATORY SYSTEM                        |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Inflammation, Chronic Active         |                            2                                             |             
      Mineralization                       |                                                                          |             
      Thrombosis                           |                                                                          |             
      Alveolar Epithelium, Hyperplasia     |          2                                2                             2|             
      Alveolus, Infiltration Cellular,     |                                                                          |             
           Histiocyte                      |                            3        3                                    |             
      Mediastinum, Inflammation, Chronic   |                                                                          |             
          Active                           |                         2                                                |             
      Pleura, Inflammation, Chronic Active |                               2                                          |             

                                            __________________________________________________________________________|             
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Foreign Body                         |                                                                          |             

                                            __________________________________________________________________________|             
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             

 _____________________________________________________________________________________________________________________|             
 SPECIAL SENSES SYSTEM                     |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Eye                                     | +                                                                        |             

                                            __________________________________________________________________________|             
   Harderian Gland                         | +                                                                        |             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM                            |                                                                          |             
                                           |                                                                          |             

                                            __________________________________________________________________________|             
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 _____________________________________________________________________________________________________________________              
                                           | 7| 7| 7| 7| 7| 7| 7| 7| 7| 7| 0| 6| 7| 7| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7|             
                             DAY ON TEST   | 3| 2| 3| 3| 3| 3| 3| 2| 3| 3| 0| 2| 3| 3| 8| 8| 8| 8| 8| 8| 8| 3| 3| 2| 3|             
                                           | 0| 9| 0| 0| 0| 0| 0| 9| 1| 0| 3| 1| 1| 0| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 1|             

 _____________________________________________________________________________________________________________________|             
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|             
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|             
    6 MG/KG                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6| 6| 6| 6| 6| 6| 6| 6| 6| 6| 7| 7| 7| 7| 7| 7|             
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5|             

 _____________________________________________________________________________________________________________________|             
 URINARY SYSTEM - cont                     |                                                                          |             
                                           |                                                                          |             
          Cell                             |    1     1  1     1  1     1        1  1           1        1  1  1     1|             
      Mineralization                       | 1  1  1  1  1  1  1  1     1     1  1  1  1  1           1     1  1  1  1|             
      Nephropathy                          | 1  2  2  1  2  2  1  2  2  1        1  1  1  1  1     1  1  1  2  2  1  2|             
      Cortex, Cyst                         |                         2        2                                2     2|             
      Renal Tubule, Hyperplasia            |                                                                   2      |             

                                            __________________________________________________________________________|             
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|             
      Infiltration Cellular, Mononuclear   |                                                                          |             
          Cell                             |    1                       1                          1           1      |             

 _____________________________________________________________________________________________________________________|             
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 3| 2| 2| 1| 2|            |
                                           | 1| 3| 9| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 9| 0| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  4.0|

                                            __________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Peyer's Patch, Hyperplasia, Lymphoid |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  M  +  +  +  +|  49        |

                                            __________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Basophilic Focus                     |          X                                                               |      2     |
      Clear Cell Focus                     |       X                                                                  |      4     |
      Eosinophilic Focus                   | X                                                                    X   |      3     |
      Hematopoietic Cell Proliferation     |                                                                          |      1  1.0|
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                   1                                                      |      6  1.0|
      Inflammation, Chronic Active         |       1     1                    1     1  1  1  1  1           2         |     21  1.1|
      Mixed Cell Focus                     | X                                                                        |      2     |
      Pigmentation                         |                                                    2                     |      3  1.3|
      Bile Duct, Cyst                      |                                                                          |      1  3.0|
      Bile Duct, Hyperplasia               |                                                                          |      1  3.0|
      Hepatocyte, Vacuolization Cytoplasmic|       1     2              2              2     1  2  1     2            |     16  1.6|

                                            __________________________________________________________________________|____________|
   Mesentery                               |                                                                          |   1        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Oral Mucosa                             | +                    +     +        +        +                          +|  10        |
      Gingival, Foreign Body               | X                    X     X        X        X                          X|     10     |
      Gingival, Inflammation, Acute        |                      1              1        1                          1|      6  1.2|
      Gingival, Inflammation, Chronic      |                                                                          |            |
          Active                           | 2                                                                        |      2  2.0|

                                            __________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |                                                                          |      1  2.0|
      Artery, Mineralization               |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1     1              1  1  1  1     1  1     1           1  1  1  1      |     29  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 3| 2| 2| 1| 2|            |
                                           | 1| 3| 9| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 9| 0| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 ALIMENTARY SYSTEM - cont                  |                                                                          |            |
                                           |                                                                          |            |
      Epithelium, Hyperplasia              |                                                                      1   |      1  1.0|

                                            __________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Mineralization                       |       1  1                                                               |      2  1.0|
      Glands, Ectasia                      |                                                             1            |      5  1.2|

                                            __________________________________________________________________________|____________|
   Tooth                                   |                                                                          |   2        |
      Malformation                         |                                                                          |      2     |

 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |                                                                          |      1  2.0|
      Mineralization                       |                                                                          |      1  2.0|

 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 1                                                                        |      7  1.4|
      Hypertrophy                          | 2                       1                       2           1           2|     15  1.6|
      Capsule, Hyperplasia                 | 2     2  1  1  1  1  1     1  1  1  1     1  2     1  1  1  1  1  1  1  1|     45  1.3|

                                            __________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hyperplasia                          | 2  2  2  2  2  2  2  2  2  2  2  2     2  2     2  2  2  2  2  2  2  2  2|     46  2.1|

                                            __________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  M  +  M  M  M  M  +  +  +  M  +  +  +  +  +  +  +|  38        |
      Cyst                                 |                                                       2                  |      1  2.0|

                                            __________________________________________________________________________|____________|
   Pituitary Gland                         | +  I  +  +  +  +  I  +  +  +  +  +  +  I  +  +  +  +  I  +  +  +  +  +  +|  46        |
      Atypia Cellular                      |                                                                          |      1  2.0|
      Pars Distalis, Cyst                  |                                                                          |      3  1.3|

                                            __________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
                                           |                                                                          |            |
    None                                   |                                                                          |            |

 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Coagulating Gland                       |                                                          +           +   |   2        |

                                            __________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1                    1     1           1        1                 1  1  1|     21  1.0|
      Inflammation, Chronic Active         |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 3| 2| 2| 1| 2|            |
                                           | 1| 3| 9| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 9| 0| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 GENITAL SYSTEM - cont                     |                                                                          |            |
                                           |                                                                          |            |
          Cell                             | 1           1     2     1  1  1  1  1  1           1           2     2   |     26  1.3|
      Inflammation, Chronic Active         |                                  2                             4         |      3  2.7|
      Duct, Cyst                           | 2     3                       2  2                 3        3            |     16  2.4|

                                            __________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |       1  1     1  1  1              1  1     1  1  1  1  1  1        1  1|     32  1.0|

                                            __________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Lymph Node                              |                                                                   +      |   1        |

                                            __________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  +  +  +  +  +  M  +  +  M  +  +  +  +  +  +  +  +  +  I  +|  47        |

                                            __________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  M  +  +  +  +  +  M  +  +  +  M  +  +  +  +  +  +  +  +  +  +  +  +  +|  47        |
      Inflammation, Chronic Active         |                                                                          |      1  3.0|

                                            __________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Hematopoietic Cell Proliferation     |                                                             2  2  3  3   |      4  2.5|

                                            __________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  49        |
      Cyst                                 |       1     1  1  2        2     1  2                    2  2           1|     17  1.5|
      Ectopic Parathyroid Gland            |                                                                          |      1  1.0|

 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  +  M  M  M  M  +  M  M  M  M  M  M  M  M  M  M|   2        |

                                            __________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

                                            __________________________________________________________________________|____________|
   Skeletal Muscle                         |                                                                   +      |   1        |

 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Inflammation, Chronic Active         |    3  1                                                        1         |      4  1.8|
      Mineralization                       |       1                                                                 1|      2  1.0|
      Thrombosis                           |    3                                                                     |      1  3.0|
      Alveolar Epithelium, Hyperplasia     |                                                                      1   |      4  1.8|
      Alveolus, Infiltration Cellular,     |                                                                          |            |

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
NTP Experiment-Test: 88050-06                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: CHRONIC                                         METHACRYLONITRILE                                     Date: 10/25/99  
Route: GAVAGE                                                                                                     Time: 08:33:12  
                                                                                                                                    

 __________________________________________________________________________________________________________________________________ 
                                           | 7| 6| 7| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 4| 7| 7| 7| 7| 7|            |
                             DAY ON TEST   | 3| 2| 2| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 3| 2| 2| 1| 2|            |
                                           | 1| 3| 9| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 0| 9| 9| 0| 9|      T (*) |

 _____________________________________________________________________________________________________________________|            |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|      A     |
    6 MG/KG                                | 7| 7| 7| 7| 8| 8| 8| 8| 8| 8| 8| 8| 8| 8| 9| 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|      L     |
                                           | 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0| 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|            |

 __________________________________________________________________________________________________________________________________ 
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |                                                                          |            |
           Histiocyte                      |                                                    2                     |      3  2.7|
      Mediastinum, Inflammation, Chronic   |                                                                          |            |
          Active                           |                                                                          |      1  2.0|
      Pleura, Inflammation, Chronic Active |                                                                          |      1  2.0|

                                            __________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Foreign Body                         | X                                                                        |      1     |

                                            __________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |

 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Eye                                     |                                                                          |   1        |

                                            __________________________________________________________________________|____________|
   Harderian Gland                         |                                                                          |   1        |

 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |                                                                          |            |

                                            __________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             |             1        1     1              1  1     1  1     1           1|     22  1.0|
      Mineralization                       | 1  1  1        1  1  1  1           1  1     1  1  1     1  1  1     1  2|     36  1.0|
      Nephropathy                          | 2     1  1     1  1  1  1     1     1        1        1  1  1  1  2  1  2|     39  1.3|
      Cortex, Cyst                         |                            2           2                 2     2  2      |      9  2.0|
      Renal Tubule, Hyperplasia            |       2                                                                  |      2  2.0|

                                            __________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +  +|  50        |
      Infiltration Cellular, Mononuclear   |                                                                          |            |
          Cell                             | 1  1  1                    1                       1           1         |     10  1.0|

 __________________________________________________________________________________________________________________________________ 

  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                             ------------------------------------------------------------                                           
                             ----------              END OF REPORT             ----------                                           
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