Profiling postprandial thermogenesis in muscle and fat of sheep and the central effect of leptin administration

Brown adipose tissue thermogenesis is an important component of energy expenditure as exemplified in rodents. Other tissues such as white adipose tissue and muscle are also capable of thermogenesis, but regulation of heat production in these tissues is poorly understood. We used a relatively large animal model, the ovariectomized sheep, in which site-specific temperature measurements were made as an index of thermogenic output. Dataloggers were implanted into the retroperitoneal (visceral) fat, gluteal (sc) fat, and skeletal muscle of the hind limb, and were programmed to record temperature every 15 min. Animals (n = 4) were then placed on a feeding schedule (fed between 1100 and 1600 h) to entrain a postprandial response in thermogenesis. Baseline thermogenesis (0800–1100 h) was higher (P < 0.05) in visceral fat and muscle than in gluteal fat, whereas the amplitude of the postprandial increase was similar at all three sites. Intracerebroventricular infusion into the lateral ventricle of either vehicle (a...