Features of Morphological Rearrangements of Structural Components in the Rat Pineal Gland Under the Impact of Heavy Metal Salts

Abstract

The development of the pathology of individual organs and systems undoubtedly depends on adverse environmental factors. Particular attention of researchers attracts heavy metal salts. Epiphyseal hormones play a key role in regulating and maintaining basic body functions. The article presents the results of the study on morphological and morphometric rearrangements of structural changes in the rat pineal gland influence for 30 days of heavy metal salts (sulfates of zinc, copper, iron, manganese, plumbers’ nitrite and chrome oxide). The selected concentration of salts in the mixture was due to the presence of similar concentrations of these salts in the soil and drinking water in some regions of Ukraine according to literature sources. General morphological and statistical research methods were used (histological, morphometric and variational statistics methods). The 30-days impact of the heavy metal salts combination on the rat body caused in the pineal gland morphological changes of nonspecific polymorphic nature, which were expressed in the increased vascular area, active glial response, hypertrophy of pinealocyte nuclei and increase of their optical density. Cytological signs in most pinealocytes indicated the predominance of indolamine synthesis over polypeptides. The main pathogenetic mechanisms of the influence of heavy metal salts on the organ have been established: change in the vascular lumen area, blood rheological properties impairment, tissue hypoxia, nucleus hypertrophy and change in their optical density. Morphological changes in the gland comply with the stress phase of the general adaptation syndrome. The above morphological changes negatively affected the processes of hormones evacuation into the blood, the course of the general adaptation syndrome and the homeostasis restoration in the organ.