Friedman J M
Howard Hughes Medical Institute, New York, New York, USA.
Nutr Rev. 1998 Feb;56(2 Pt 2):s38-46; discussion s54-75. doi: 10.1111/j.1753-4887.1998.tb01685.x.
The assimilation, storage, and disposition of nutrient energy constitute a complex homeostatic system central to the survival of both prokaryotic and eukaryotic organisms. In vertebrates, and especially among land dwelling mammalian species, the ability to store large quantities of energy-dense fuel in the form of adipose tissue triglyceride permits survival during prolonged periods of food deprivation. In order to maintain such fuel stores during times of dietary scarcity or surfeit, some balance between energy intake and expenditure must be achieved. Lesions of the hypothalamus alter body weight suggesting that this brain region regulates nutritional state. These and other studies led to the hypothesis that body weight was regulated by a feedback loop in which peripheral signals reported nutritional information to an integratory center in the brain. However, the identity of these nutrition signals proved elusive.
营养能量的同化、储存和分配构成了一个复杂的稳态系统，这对于原核生物和真核生物的生存都至关重要。在脊椎动物中，尤其是在陆生哺乳动物物种中，以脂肪组织甘油三酯的形式储存大量能量密集型燃料的能力使得动物能够在长期食物匮乏期间存活下来。为了在饮食不足或过剩时维持这种燃料储备，必须在能量摄入和消耗之间达到某种平衡。下丘脑损伤会改变体重，这表明该脑区调节营养状态。这些研究以及其他研究导致了这样一种假说，即体重是由一个反馈回路调节的，在这个回路中，外周信号将营养信息报告给大脑中的一个整合中心。然而，这些营养信号的身份却难以捉摸。
