Ventromedial hypothalamic stimulation accelerates norepinephrine turnover in brown adipose tissue of rats.

To establish a functional link between the ventromedial hypothalamus (VMH) and brown adipose tissue (BAT), effects of electrical stimulation of the VMH and the lateral hypothalamus (LH) on norepinephrine (NE) turnover in the interscapular BAT were examined in rats. Stimulation of the VMH elicited about 3-fold increase in the rate of NE turnover in BAT, whereas stimulation of the LH had no appreciable effects. The effect of VMH stimulation was abolished after sympathetic ganglion blockade or by surgical sympathetic denervation of BAT. It was concluded that there is a sympathetic nerve-mediated connection between the VMH and BAT, and that stimulation of the VMH induces metabolic activation and heat production in BAT through an increase in sympathetic nerve activity.