Adaptive thermogenesis of brown adipose tissue in tree shrews (Tupaia belangeri): Role of melatonin

By regulating the pineal hormone, photoperiods affect many physiological characteristics in small mammals. Thus, melatonin might take part in the thermoregulation of seasonal variations in small mammals. In this study, we examined the influence of melatonin treatment on body mass as well as on several physiological, hormonal, and biochemical measures indicative of thermogenic capacity, to test our hypothesis that melatonin stimulates increases thermogenic capacity and energy intake in tree shrews. At the end, these tree shrews (MLT) had a significant higher body mass, energy intake, cytochrome C oxidase (COX) and thyroxin 5’-deiodinase (T4 5’-DII) activity, uncoupling protein-1 (UCP1) contents, serum tri-iodothyronine (T3) and Thyroid-stimulating Hormone (TSH) compared to control or PBS group tree shrews, but there was no significant in serum leptin and melatonin in the three groups. Together, these data indicate that melatonin enhances thermogenic capacity in tree shrews. Our results suggested that melatonin is potentially involved in the regulation of body mass, adaptive thermogenic capacity and hormone concentrations in tree shrews.