Gevorkyan A. Impact of melatonin on daily rhythms of functional activity of the pineal gland and the hypothalamic-pituitary-thyroid system in aging (experimental study)

The object of study: functional status of the pineal gland of pituitary-hypothalamic-thyroid system for young and old rat of Wistar population. The aim of research: determine features of the influence of exogenous melatonin on the circadian rhythms of hormonal activity and the morphofunctional state of the thyroid gland and its neuroendocrine regulatory centers of old rats. The methods of research: immunoenzymatic, radionuclide, histological, histochemical, morphometric, statistics. For the first time given a comprehensive assessment of changes of daily rhythms of pineal gland functioning of the hypothalamic-pituitary-thyroid system in the descending phase of ontogeny. Established hormonal and structural correlates of functioning of the thyroid gland and its neuroendocrine regulatory centers (pituitary, pineal gland), depending on age and time of day. Proved that old rats with age-dependent hypothyroidism (as opposed to younger) have exogenous melatonin in the doses used detects prothyroidal dose-dependent effect. Dose of exogenous melatonin, with due consideration of hormonal activity and structural features, not only for thyrocytes thyroid gland, but for epiphysial pinealocytes, pituitary thyreotropocytes and suprachiasmatic nucleus of the hypothalamus. The experimental data can be regarded as a theoretical basis for the feasibility of using medication melatonin in elderly and senile patients with hypothyroidism. The sphere of application: endocrinology, gerontology.