A study of the effect of antral distension on gastric acid secretion in man.

In 30 healthy subjects distension of the antrum by a 150-cm3 balloon reduced the acid and volume responses to submaximal stimulation achieved by a continuous intravenous infusion of pentagastrin. The inhibition persisted during perfusion of the stomach with alkaline buffer. The plasma somatostatin concentration did not increase during distension and no somatostatin was detected in the gastric contents. Balloon distension of the antrum during laparotomy did not affect the concentration of somatostatin and gastrin in portal blood in patients with gallbladder disease or duodenal ulcer. The results confirm that antral distension stimulates acid secretion in duodenal ulcer patients without involvement of the gastrin mechanism. Moreover, the inhibition of acid secretion by antral distension in healthy subjects is independent of luminal pH and does not appear to be mediated by somatostatin.