GLUCAGON-LIKE PEPTIDE-1 (7-36)-AMIDE ADMINISTERED INTO THE 3RD CEREBROVENTRICLE INHIBITS WATER-INTAKE IN RATS

Intracerebroventricular (icv) injection of glucagon-like peptide-1 (7- 36) amide (GLP-1) has been shown to reduce food intake in rats. In the se studies, we confirmed that injection of 10 mu g of GLP-1 into the t hird cerebroventricle suppressed food intake. Moreover, we observed a reduction in water intake associated with the decreased food intake. W e further examined whether GLP-1 injected icy in rats has a specific i nhibitory effect on water intake. It was found that GLP-1 reduced wate r deprivation-induced drinking. Furthermore, the same dose of GLP-1 (1 0 mu g) was sufficient to condition taste aversion. Finally, when 2 mu g of GLP-1 were injected into the third ventricle, it only suppressed water deprivation-induced water intake and failed to influence sponta neous food and water intakes or induce conditioned taste aversion. The se observations indicate that GLP-1 is a potent inhibitor of water int ake in the rat and may play a role in the control of fluid homeostasis .