Humoral control of hyper- and hypometabolic states.

It is concluded that besides NA, some other hormones (adrenaline, glucagon, growth hormone, ACTH, insulin and adrenal steroids) are also thermogenic. While brown adipose tissue is the most important site of heat during NA thermogenesis, some other organs, namely muscles, also contribute to thermogenesis due to various hormones. Hormones seem to potentiate heat production due to their action in target organs. Humoral thermogenesis not only can compensate the heat loss from the body of cold exposed individuals, but it can also prevent obesity under conditions of an high caloric intake. Some substance, on the other hand, induce a hypometabolic effect (rT3, hibernation trigger, antabolone, bombesin). Additionally, absence of gonadal steroids induce hibernation. Thus, humoral substances contribute both to the control of hyper- and hypometabolic states.