Hypothalamus, sympathetic nerve and brown adipose tissue in the regulation of energy balance.

棕色脂肪组织（BAT）是冷适应和自发性摄食过程中化学产热的主要部位。有人提出BAT产热功能受损是导致肥胖的一个因素。本课题研究了大鼠下丘脑和交感神经系统对BAT产热相关代谢的调节作用.电刺激下丘脑腹内侧核（VMH）引起肩胛间BAT中去甲肾上腺素周转率的增加，这是该组织中交感神经活动的指数，与BAT温度和葡萄糖利用率的特定增加平行。手术切除交感神经后，对VMH刺激的产热反应完全消失。这些结果表明VMH通过交感神经系统的作用控制BAT的热发生。2. VMH损伤的大鼠出现暴食和肥胖。在这些动物中，BAT的代谢和产热活性显著降低，支持BAT产热功能受损有助于下丘脑肥胖的发展.与经口喂食的大鼠相比，灌胃喂食的大鼠表现出较低的BAT产热活性，并且变得更肥胖，尽管它们得到的食物量相同。结果表明，口咽部的感觉BAT产热的刺激作用。

Brown adipose tissue (BAT) is known as a major site for chemical thermogenesis during cold acclimation and spontaneous hyperphagia. It has been proposed that the impairment of BAT thermogenesis is a factor contributing to the development of obesity. In this project, we studied regulatory roles of the hypothalamus and sympathetic nervous system for BAT thermogenesis-linked metabolism in rats.1. Electrical stimulation of the ventromedial nucleus of the hypothalamus (VMH) elicited an increase in norepinephrine turnover in the interscapular BAT, an index of sympathetic nerve activity in this tissue, in parallel with a specific increase in BAT temperature and glucose utilization. The thermogenic response to VMH stimulation was completely abolished after surgical sympathetic denervation. These results indicate that the VMH controls BAT themogenesis through the action of sympathetic nervous system.2. Rats with lesions in the VMH became hyperphagia and obese. In these animals, metabolic and thermogenic activities of BAT were remarkably decreased, supporting an idea that impaired BAT thermogenesis contributes to the development of hypothalamic obesity.3. Rats fed intragastrically, compared with those fed orally, showed lower BAT thermogenic activity and got more obese, although they were given the same amount of food. The results suggest a stimulatory role of oropharyngeal sensations for BAT thermogenesis.