One of the prominent obesity-related changes is the development of systemic low-grade proinflammatory state. Brown adipose tissue (BAT) may serve as a potential target for activation by melatonin to facilitate heat production and simultaneouslystimulatelipolysis during obesity development.At the same time, melatonin is known to have immunomodulatory properties, which are performed via endocrine and paracrine signal pathways in variety cell types (including brown adipocytes)and change significantly during the day. Therefore, it can be used in a wide range of doses and at different times of the day (chronotherapeutic approach). Thus, the main goal of our research was to analyze the inflammation state of brown adipose tissue of rats during high-calorie diet induced-obesity development after different daily melatonin application in different regimes. Melatonin was administered by gavage for 7 weeks in dose 30 mg/kg 1 h before lights-off (HCD ZT11, M ZT11, evening), or 1 h after lights-on (HCD ZT01, M ZT01, morning). Tissue collagen contain and leukocyte infiltration levels in BAT, detected by Van Gieson trichrome staining, were used as markers for assessment of BAT inflammation state BAT.Propagation of obesity resulted in the increase of BATfibrosis& level (the relative area occupied by collagen fibers) and tissue leukocyte infiltration in comparison to control rats. BAT fibrosis level after melatonin administrations to obese rats of HCD ZT01 and HCD ZT11 groups decreased to control values.Simil&ar effectswere observedinBAT tissue leukocyte infiltrationafter both regimes (HCD ZT01 and HCD ZT11 groups) of melatonin intake: this parameter decreased significantly, comparing to obese rats, but was still elevated, comparing to controls. At the sa&me time, melatonin treatmentin morning or evening regimes did not have any impact on BAT fibrosis propagation and leukocyte infiltration in animals that consumed standard diet (M ZT01 and M ZT11 groups). To sum up, we suggestcorrectivepropertiesof me&latonin in context of chronic low-grade inflammation in obese rats BAT and suppose its wide potential for the therapeutic usecombined withvirtually absent side effects on BAThistophysiology of non-obese rats.
З 31.12.2014 по 01.03.2015 Наукова бібліотека читачів не обслуговує.
