MORPHO-FUNCTIONAL CHARACTERISTICS OF THE BONE TISSUE AT EXOGENOUS INTOXICATION IN RAT EXPERIMENTS
The author of this pilot study investigates the morphological changes in the bone tissue in chronic low doses of two toxicants with different mechanisms of action in the body. Quantitative determination included the calculation of the average thickness of the cortical bone, trabecular bone, the volume fraction of the bone tissue, the numerical density of cells immunopositive to osteonectin, a marker of ma crop hages a nd osteoclas ts, matr ix metalloproteinases MMP-9 and its tissue inhibitor TIMP-1. The factors causing disturbances in regenerative function of bone tissue include not only internal factors of the environment, but also the impact of external conditions, such as the toxic effects of chemicals. Toxicants from the environment, cumulated in different tissues of the body can cause systemic pathological changes in their functioning. Chronic intoxication is accompanied by violations of the natural regeneration of bone tissue, resulting in firstly increased and then decreased regenerative capacity of tissues to intensify the process of resorption of bone matrix and osteoporosis symptoms development. There was a predominance of the processes of destruction of bone fixation processes. The volume fraction and decreased bone mass, the fabric becomes more friable porous structure, whereby there was a decrease of bone strength and increase in its brittleness. The resorbable bone osteoclast showed predominance destroying extracellular matrix, while the number of osteoblasts is decreased. It is shown that the identification of the morphological study of the bone tissue of these features can be considered as one of the indicators of chronic toxic effects of chemical environmental factors on the body.