Inhibition by secretin of the gastric acid responses to meals and to pentagastrin in duodenal ulcer patients

The inhibitory effects of intravenous secretion on the gastric acid responses to a meal and to pentagastrin were studied in seven duodenal ulcer patients.A test meal of 10% peptone adjusted to pH 5.0 was introduced into the stomach and the Fordtran and Walsh method was used to measure the gastric acid output by monitoring the rate at which a solution of 0.3 M sodium bicarbonate had to be added to keep the pH of the gastric content constant at the value of 5.0. A constant dose of secretin (1 U/kg-hr) significantly depressed the serum gastrin response to a meal and produced an inhibition of acid secretion by about 70% of the control level. Secretin inhibited the acid response induced by pentagastrin by about 60% and simultaneously provoked a pancreatic bicarbonate output sufficient to neutralize about 60% of the gastric acid output to pentagastrin. We conclude that secretin is a strong inhibitor of gastric secretion in duodenal ulcer patients induced by a meal and by pentagastrin.