DYNAMIC CHANGES IN THE BONE MARROW CELLULAR COMPOSITION OF RATS IN THE BURN WOUNDS HEALING IN NORM AND IN CONDITIONS OF HYPERGLYCEMIA
Authors: Rizhko I.M. , Natrus L.V. 
Published: September 2019

Relevance.  Today the study of the potential of hematopoietic progenitors is particular relevance in connection with the use of hematopoietic cells as the main material of transplantation for the treatment of various diseases including trophic ulcers in diabetes mellitus.

Objective is study the dynamic fluctuations of the cellular composition of the bone marrow (ВM) of rats according to myelogram indices during the healing of a burn wound in normal conditions and in conditions of hyperglycemia.

Materials and methods. The study of dynamics (3, 7, 14, 21 days) of burn wound of skin of rats of the Vistar line without somatic pathology "control group" (n=24) and rats (n=24) with experimental streptotrozine diabetes mellitus (CD) (Blood glucose level – 24,24±0,79 mmol/L against 8,03±0,4 mmol/L in the control group). Under etheric anesthesia the burn was simulated using copper plates in the form of an ellipse. The total area of skin burn was 18-20 % of the body surface. The study of myelogram was carried out according to the standard method of M. Arinkkin the material of the bone marrow was washed from the distal end of the femur. The stroke was fixed with ethanol and stained with Romanovsky-Gimza. On each glass 500 cell elements were counted the number of cells of each species was determined and converted to percentages. Microscopy was performed under imesium at an increase of 100×10. All indicators in healing dynamics were compared with those of myelogram which were determined in the group (n = 12) of healthy rats who did not reproduce the burn. Their indicators were considered to be referential values (RZ). Statistical data was processed using IBM SPSS Statistics 23.

Results. In normal wound healing is accompanied by a general increase in the proliferation of myeloid splenectomy with a slight oppression of 7 days. At the same time in all terms of observation the proliferation of elements of erythroid origin of BM decreases but their functional capacity and hemoglobin saturation remains normal. The differentiation of cellular elements in the BM also increases but differ in terms. Up to 3 days mature granulocytes and monocytes are actively differentiated. At 7th day  in the BM the relative number of eosinophils and basophils is increased. Probably such a redistribution reflects the regulation of cell reproduction in the BM for their release into the peripheral bloodstream and subsequent participation in the process of regeneration of the connective tissue which provides normal physiological healing.

Under conditions of hyperglycemia the difference in the cellular composition of the BM is already at the stage of the common polypotent precursors: the proliferation of common cells of lymphoid origin increases 1,5-fold and due to this the content of myeloid contraction is reduced. On all terms of observation in 1,4 times the proliferation of erythrocyte precursors predominates and the total proliferative activity of granulocytic precursors increases by 2,5 times. Due to this in 1,5-2 times the differentiation of granulocytes decreases. Particularly sensitive to hyperglycemia was the growth of basophils and monocytes which in BM was 1,5-2,8 times smaller and the dynamics of changes in terms of observation also differed from control.

Conclusion: The effect of hyperglycemia on proliferation capacity and activity differentiation in BM causes a redistribution of cellular elements reflected on the number and functional ability of cells involved in providing and regulating signaling during connective tissue regeneration. Changes in the relative content of cellular progenitors in BM and the late release of cells from BM to peripheral blood can cause a violation of the connective tissue regeneration scenario and cause trophic ulcers or non-healing wounds in diabetes.