Effect of duodenal fat on plasma levels of gastrin and secretin and on gastric acid responses to gastric and intestinal meals in dogs.

The effects of duodenal instillation of sodium oleate (10 mmoles per hr) on plasma levels of gastrin and secretin and on gastric acid secretion in response to gastric and intestinal meals were determined. Four dogs prepared with a septum between stomach and duodenum were provided with a special cannula that allowed separate access to the stomach or duodenum. Each dog received a 10% liver extract meal introduced either into the stomach (gastric phase) or into the duodenum (intestinal phase). Sodium oleate administered during the gastric phase caused approximately a 30% reduction in plasma gastrin level and a 25% inhibition of gastric acid secretion. Sodium oleate given during the intestinal phase completely abolished the plasma gastrin response and resulted in a 75% inhibition of gastric acid secretion. Plasma secretin levels were not changed during the gastric phase or the intestinal phase by instillation of sodium oleate. These results show that fat in the duodenum is a potent inhibitor of gastrin release and gastric acid secretion; the intestinal mechanism involved does not appear to affect plasma secretin concentrations.