The development of the pathology of individual organs and systems undoubtedly depends on adverse envi­ronmental factors. The heavy metal imbalance affects the health of the population and may lead to unpredict­able consequences. Тhe hormones of the intermediate part of the pituitary gland are one of the key places in regulating and maintaining the basic functions of the organism. Тhe question of the influence on the intermediate part of the pituitary gland of the combination of heavy metal salts remains relevant and insufficiently studied. In order to study the morph functional rearrangements of the structural components of the intermediate pitu­itary gland of sexually mature female rats, an experiment was conducted on 12 animals weighing 250–300 g, aged 7–8 months. The animals of the experimental group consumed normal drinking water saturated with a combination of salts of heavy metals for 60 days. Morphometric, statistical, immunohistochemically, biochemi­cal, and histological methods were used. Significant thickening and edema of the inter trabecular connective tissue septum, depletion of capillaries and morphological rearranging part of the troposites, mainly their nuclear apparatus (condensation of chromatin and its marginal location, initial stages of necrobiotic changes), is manifested. Prolonged intake of sexually mature female rats of heavy metal salts leads to morph functional rearrangements of all structural components of the intermediate lobe of the pituitary gland. The above morph functional changes are of a non-specific polymorphic nature and are characteristic of the stage of increased re­sistance of the general adaptation syndrome.

An important environmental problem is the pollution of the environment with heavy metal salts, which are in various combinations depending on the region and cause adverse effects on public health. The endocrine system together with the immune and nervous system maintains homeostasis in the body. In order to study the morphofunctional rearrangements of the epiphyseal-parathyroid axis structural components in rats during 30 days of readaptation after 90 days of exposure to heavy metal salts (zinc (ZnSO4 · 7H2O) — 5 mg/l, copper (CuSO4 · 5H2O) — 1 mg/l, iron (FeSO4 ) — 10 mg/l, manganese (MnSO4 · 5H2O) — 0.1 mg/l, lead (Pb(NO3 ) 2 ) — 0.1 mg/l and chromium K2Cr2O7) — 0.1 mg/l) an experiment was performed on 24 white sexually mature male rats weighing 250–300 g, aged 7–8 months. The animals of the experimental group consumed ordinary drinking water for 30 days. Morphological, statistical, immunohistochemical and biochemical research methods were used. The 30-day period of readaptation after 90 days of heavy metal salts intake is insufficient to completely restore homeostasis in the epiphyseal-parathyroid system, which is at the stage of chronic stress «subcompensation». Significant morphological changes on the part of the vascular bed of the pineal gland and parathyroid glands (blood stasis, erythrocyte aggregation, sludge phenomenon) were determined, an active glial reaction was formed in the pineal gland, and the structure of the epithelial trabeculae of the glands was disturbed. The levels of parathyroid hormone and calcium in the blood of experimental animals were significantly lower than those of experimental animals. There is a greater vulnerability and faster dynamics of the regenerative processes in the parathyroid glands to the action of salts of heavy metals in comparison with the pineal gland. The development of hypofunction of the parathyroid glands, of course, has a negative effect on the overall calcium metabolism in the body, the development of compensatory and adaptive processes and the course of the general adaptation syndrome in response to the damaging agent.

The monograph presents a theoretical generalization and a new solution for the research target to study the state of the pineal gland structural components in sexually mature rats under different terms of extracellular dehydration. The experiment was performed on 24 white sexually mature male rats aged 5-6 months. The animals of the experimental group were simulated extracellular dehydration of mild and heavy severity. Animals were kept and manipulated in compliance with national and international bioethics standards. Different degrees of extracellular dehydration severity caused negative changes in all structural components of the pineal gland in experimental animals: stromal, vascular and parenchymal, with the greatest intensity in animals with heavy severity course. Morphological rearrangements were nonspecific and polymorphic in nature. In the pineal gland of animals with a mild severity course there was a tension of adaptive processes, increased secretory activity by both indole-producing and polypeptide-producing pinealocytes (with predominance of the latter), formation of the gland’s reserve capacity. There was a moderate increase in the expression of heat shock proteins in pinealocytes, which, certainly, made these cells more resistant to apoptotic rearrangements and the subsequent action of extreme factors. With increasing duration of the experiment (severe degree), there was a significant decrease in the size of the gland, thickening and swelling of the stromal component, sharp impairment of hemodynamics in the organ. Blood viscosity increased, its rheological properties were impaired (stasis, sludge), vascular wall permeability increased, processes of accelerated apoptosis in part of pinealocytes developed. The heat shock proteins level and the proliferative activity of astrocytic glia were significantly reduced, indicating a weakening of the mechanisms of anti-apoptotic and anti-stress protection. The 90-day effect of extracellular dehydration on the experimental animals’ body caused the phenomenon of chronic stress “subcompensation”, which was expressed in the depletion of pineal indolamines reserve and their urgent evacuation into the blood to maintain general adaptive capacity of the body. However, disturbances in the morphology of the vascular wall and increased blood viscosity negatively affected the mechanisms of pineal hormones diffusion into the vascular bed, the development of compensatory-adaptive processes in the body as a whole and the course of general adaptation syndrome.

Статтю отримано 29 листопада 2018 р.; прийнято до друку 10 січня 2019 р.Анотація. Солі важких металів негативно впливають на здоров'я населення та викликають розвиток патології окремих органів та систем організму. Гормони надниркових залоз займають одне з ключових місць у регуляції та підтриманні основних функцій організму. Мета дослідження -вивчення морфологічних перебудов структурних компонентів кіркової речовини наднирників статевозрілих щурів-самців в умовах довготривалого впливу комбінації солей важких металів. Експеримент був проведений на 12 тваринах масою 250-300г віком 7-8 місяців. Тварини експериментальної групи протягом 90 діб вживали звичайну питну воду, насичену комбінацією солей важких металів. Застосовували загальноприйняті гістологічні методи дослідження. Довготривале надходження до організму статевозрілих щурів комбінації солей важких металів призводить до морфологічних перебудов строми, судинного русла, морфології та секреторної активності спонгіоцитів, переважно, пучкової та сітчастої зон. Розвиток у спонгіоцитах ліпідної вакуолярної та зернистої дегенерації вказує на послаблення стероідогенезу, що негативно впливає на розвиток в організмі компенсаторно-пристосувальних процесів та перебіг загального адаптаційного синдрому у відповідь на дію пошкоджуючого агента. Отже, у корі наднирників розвиваються пристосувально-компенсаторні процеси з ознаками зниженої функціональної активності, що характерне для початкових етапів виснаження загального адаптаційного синдрому. Перспективи подальших розробок базуються на проведенні досліджень наднирників щурів в умовах репаративних змін після довготривалих термінів впливу комбінації солей важких металів на організм.©Вінницький національний медичний університет ім. М.І. Пирогова " Вісник Вінницького національного медичного університету", 2019, Т. 23, №1 ІSSN 1817-7883 eІSSN 2522-9354

The article presents the results of the study on morphological rearrangements of structural changes in the rat pineal gland under the influence of heavy metal salts and correction with L-tocopherol during 30 days. General morphological and statistical research methods were used (histological, morphometric and statistic methods). The protective effect of L-tocopherol caused in the pineal gland a number of compensatory-adaptive processes aimed at neutralizing the stressor's impact on the organ. The 30days protective period of L-tocopherol is insufficient to completely neutralize the impact of heavy metals on the organ: the glial response was activated, vascular area increased, vascular wall permeability was impaired, edema was formed and the connective tissue component growth was taking place, indicating dysfunctional reorganization in the gland's secretory activity. 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.