Kalmukova, O. O.     The effects of different time of melatonin administration on differentiation and functional status of the brown adipocytes in vivo [Текст] / O. O. Kalmukova, M. E. Dzerzhinsky // Клітинна та органна трансплантологія. - 2018. - Том 6, N 1. - С. 80-85. - Bibliogr. at the end of the art. Анотація: Recently, numerous studies have indicated that melatonin, the hormone of pineal gland, affects the processes of differentiation of many cells, including preadipocytes into brown, beige and white adipocytes. Therefore, it is important to study the possibilities of using melatonin as a factor for the differentiation of preadipocytes to control the adipose tissue functional activity in the treatment of various diseases, including obesity. The aim of the study was to evaluate the morphology and functional status of brown adipose tissue at the different time of melatonin administration. Materials and methods. Outbred rats were divided into 3 experimental groups: control, administration of melatonin 1 hour after light-on ZT01 (Zeitgeber time), administration of melatonin 1 hour before light-off ZT11. Melatonin was administered by gavage daily for 7 weeks at a standard exposure day-night light (12:12) Results. The application of melatonin affects the morphology and functional state of brown adipocytes independently of the administration time: the nuclear-cytoplasmic ratio increases due to an increase in the area of the nucleus against the unchanging cell area. The number of lipid drops increases in each adipocyte, but their size are decreased. The effect of different time of melatonin administration was manifested in the increase brown adipose tissue weight, in the terms of evening administrations. Conclusion. The effects of different times of melatonin administration at the cytological level are manifested almost identical in the brown adipocytes functional state in all experimental groups. However, at the organism level in terms of evening administrations, an increase in the relative mass of brown adipose tissue is observed, but the size of brown adipocytes do not change, which may indicate the activation of the differentiation of brown adipocytes from the progenitor cells. Дод.точки доступу: Dzerzhinsky, M. E. Экземпляры: всего 1 : чит.зал періодичних видань, рук.,кат. (1 экз.) Свободны: всего 1 : чит.зал періодичних видань, рук.,кат. (1 экз.)