Abstract

Vagal activation of gastric acid secretion by modified sham feeding in six patients with duodenal ulcer produced a peak acid response amounting to 52% of the peak acid output after pentagastrin stimulation (PAOpg). Cholinergic reflex stimulation of gastric acid secretion by fundic distension in another six patients with duodenal ulcer produced a peak acid response of 45% of PAOpg. Intravenous infusion of cimetidine in a dose of 100 mg/h markedly inhibited the acid sham feeding response by 90-100% and almost abolished the acid response to fundic distension. The results suggest that gastric acid secretion evoked by physiological vagal activation in man is profoundly inhibited by H2-receptor blocking agents.