Role of lipostatic mechanism in regulation by feeding of energy balance in rats.

Abstract

Conducted 6 experiments to investigate the existence of a fat-feeding diurnal cycle in normal and hyperphagic male and female Wistar rats. Such a cycle was found in normal but not in hyperphagic Ss. By using 14C-labeled food eaten either at night or day, it was directly shown that metabolites eaten and stored at night were mobilized during the subsequent day and predominantly used during the hours preceding the onset of each meal. From other results on relationships between fat synthesis and overeating at night, and lipolysis and undereating in the day, diurnal is concluded that a lipostatic mechanism modulates-both within the diurnal cycle and from day to day-the glucosensitive short-term control system of food intake. Disruption of this lipostatic mechanism in ventromedial hypothalamus (VMH) lesioned Ss suggests that VMH nuclei are key sites for the neuroendocrine basis of the lipostatic control of food intake. (49 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)