Effects of glucagon, secretin, and vasoactive intestinal polypeptide on gastric somatostatin and gastrin release from isolated perfused rat stomach.

To investigate the role of gastric somatostatin on gastrin secretion, glucagon, secretin, and vasoactive intestinal polypeptide (VIP) were perfused in the isolated pancreas-spleen-duodenum deprived preparation of rat stomach. After a preperfusion with 4.6% dextran Krebs-Ringer bicarbonate buffer containing 5.5 mM glucose, glucagon, secretin, and VIP at the concentrations of 10(-8), 10(-7), and 10(-6) M were infused into the left gastric artery at a constant flow of 2 ml/min for 15 min. All glucagon, secretin, and VIP evoked dose-dependent increases of somatostatin secretion with a simultaneous dose-related decrease of gastrin release. Furthermore, a significant correlation was found between the increase of somatostatin release and the decrease of gastrin secretion induced by glucagon, secretin, and VIP. These results raise the possibility that the suppression of gastrin secretion induced by glucagon, secretin, and VIP may, at least in part, be mediated by local action of gastric somatostatin.