LiCl and CCK inhibit gastric emptying and feeding and stimulate OT secretion in rats

Systemic injection of the nauseogenic agent LiCl is known to increase neurohypophyseal secretion of oxytocin (OT) in rats. The present results indicated that the induced OT secretion was related exponentially to the inhibition of food intake. A similar relation between OT secretion and food intake also was observed after systemic injection of the peptide hormone cholecystokinin (CCK). However, the effects of each agent on food intake lasted much longer than the observed increases in OT secretion. In contrast, both LiCl and CCK produced a dose-dependent inhibition of gastric emptying in rats that was closely related temporally to the inhibition of food intake. The similarity of these three responses to LiCl and CCK suggests that both agents stimulate common central mechanisms, apparently involving both magnocellular and parvocellular neurons in the paraventricular nucleus of the hypothalamus, whereby these neuroendocrine, behavioral, and autonomic functions are integrated.