Secretin: the enterogastrone released by acid in the duodenum.

215 (4): 885-888. 1968.-The inhibitory effects of intravenous infusions of secretin and intraduodenal infusions of HCl on gastric secretion were compared in dogs having Heidenhain pouches, gastric and duodenal fistulas. With the gastric fistula open a constant level of secretion was established in the Heidenhain pouch with either gastrin (0.4 or 0.8 g/kg per hr) or histamine dihydrochloride (0.04 mg/kg per hr). During this time the duodenum was infused with 154 rnM NaCl. Then either 160 mM HCl was substituted for NaCl in the duodenal infusate or a physiological dose of secretin (4 U/kg per hr) was injected intravenously. Both acid and secretin inhibited gastrin-stimulated secretion within 15 min and at 1 hr secretion was close to zero. Secretin inhibited secretion produced by 0.8 g gastrin more effectively than acid, but otherwise their effects were the same. Neither acid nor secretin inhibited histaminestimulated secretion. Therefore a physiological dose of secretin was able to account for all the. inhibition of gastric secretion seen with acid in the duodenum. We conclude that secretin is probably the only enterogastrone released by acid in the duodenum.