SUMMARY
The aim of the research was to study the features of the morphofunctional state of the pineal gland, neurohypophysis and adrenal medulla, as well as the ?ontent of serotonin and catecholamine in the blood serum of rats against the background of energy drink administration during two weeks. In animals that consumed energy drinks during two weeks at a dose of 6 ml per kg of body weight, serum serotonin and catecholamine levels were determined. Histological, including morphometric, studies of the epiphysis, posterior pituitary and adrenal medulla were performed. Against the background of energy drink administration, an increase in the content of blood serum serotonin, norepinephrine and epinephrine was detected. The morphofunctional state of the endocrine glands investigated in the present study is strongly stimulated. Indirect signs of apoptosis of parenchymal cells in the pineal gland, neurohypophysis and adrenal medulla were established. The studied stress-associated endocrine glands in animals against the background of the two-week intake of energy drinks have signs of a sharp stimulation of hormone production (serotonin, norepinephrine, epinephrine, and vasopressin).Oral consumption of energy drinks during two weeks by experimental animals led to morphological changes in the pineal gland (prevalence of indolamine-producing pinealocytes), an increased load on these cells and probably their faster and frequent apoptosis. The number of pinealocytes in the pineal gland decreases and their morpho-functional load increases.2. Short-term administration (14 days) of caffeinated energy drinks affects the morphofunctional state of posterior pituitary, which can be highly likely interpreted as a result of overproduction of vasopressin.3. Overproduction of serotonin by pynea-locytes and catecholamine by adrenal glands is confirmed by their higher levels in blood serum of animals after the two-week-long intake of energy drinks compared to the control group.