AB1044 Toxic effects of toluene vapor on growth of different bones: Tibia, vertebra, hip bone
Authors: V. Luzin, A. Yeryomin, E. Shutov, A. Skorobogatov
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Background</h3> Nontraumatic diseases of the skeletal system, such as osteoporosis, have reached epidemic proportions today. Toxic environmental factors play an important role in the pathogenesis of, but their influence has been insufficiently studied. <h3>Objectives</h3> Our aim - to study the growth characteristics of bones of white rats after a 60-day inhalation poisoning with toluene. <h3>Methods</h3> We carried out a study of 180 white adult male rats. All animals were divided into control and experimental groups. The experimental group was exposed to vapors of toluene in two months. We deduced animals from the experiment at 1, 7, 15, 30 and 60 days by decapitation under ether anesthesia. After this, we studied the morphometric parameters of bones. <h3>Results</h3> Continuous and fairly intensive longitudinal and appositional growth of all investigated bone was observed in intact rats during the experiment. This is consistent with both the literature and the results of our previous studies. After a 60-day inhalation of toluene vapors, we registered a longitudinal and appositional deceleration of growth of the bones studied, which was the highest since the 1st to the 15th day after the termination of inhalation cycle and subsequently slightly smoothed. However, 60 days after termination of the influence of toluene credible deviations remained. Thus, the maximum length of the tibia and hip bones were smaller than in group 1 to all deadlines of observation, respectively, at 4.15%, 4.47%, 2.67%, 3.35% and 3.41%, and at 3.84%, 3.78%, 4.88%, 4.16% and 2.91%. Body height third lumbar vertebra was also less than the control, respectively, at 5.12%, 6.27%, 6.69%, 3.28% and 4.80%. The transverse dimensions of the tibia were also lower than in intact rats, in all the deadlines of the experiment: the width of the proximal and distal epiphyses, respectively, at 3.69%, 4.14%, 5.77%, 4.49% and 2.84% (p&gt;0.05) and 11.94%, 7.78%, 10.75%, 10.00% and 6.86%, while the width and anterior-posterior size of the middle diaphysis - by 6.82%, 6.72%, 7.01%, 5.82% and 6.05% and 12.31%, 10.14%, 9.80%, 8.65% and 7.11%. The maximum width of the hip bone was lower than in intact animals also in all the deadlines of the experiment, respectively, at 6.06%, 6.19%, 6.89%, 4.87% and 5.53% (p&gt;0.05) and the width of the body third lumbar vertebra - at 7.27%, 7.12%, 5.90%, 5.43% and 5.69%. However, after a 60-day inhalation of toluene vapor the maximum thickness of the hip bone was less than control values of group 1 to 1, 30 and 60 days of the experiment at 5.02%, 4.78% and 10.45% and a maximum width of body third lumbar vertebrae although it was smaller, but significantly different from control values only to the 7 day - at 7.51%. <h3>Conclusions</h3> Inhaled toluene influence leads to a slowdown of both longitudinal and appositional of bone growth. The identified changes are seen at 1, 7 and 15 days after inoculation with toluene inhalation with a tendency to a leveling of 30 and 60 days. <h3>Disclosure of Interest</h3> None Declared