Effects of sham feeding and a meal on plasma gastrin and duodenal pH in normal and duodenal ulcer patients.

The roles of plasma gastrin and duodenal acidity in duodenal ulcer disease remain unclear. In this pathophysiologic study, plasma gastrin and dual gastro-duodenal pH were measured before, during, and after cephalic stimulation (modified sham feeding) and the ingestion of a meal in 16 duodenal ulcer (DU) patients and twelve healthy subjects. Gastrin levels were significantly higher in DU patients both in the fasting state (42.5 ng/l vs. 22.5 ng/l, p less than 0.001) and after the meal (130 vs. 60, p less than 0.02). Two separate patient subsets were identified: a "hypergastrinemic" (HRG) group exhibiting exaggerated gastrin responses and a "Normogastrinemic" (NOG) group comprised of patients with gastrin levels similar to those of controls. Only the HRG group exhibited a significant gastrin response to sham feeding. Both patient groups exhibited a delayed onset of duodenal acidity and delayed peak acid response after feeding indicative of delayed gastric emptying of the acid load. The HRG group exhibited a longer duodenal acid exposure and a prolonged return to premeal pH levels, suggesting a defective switch-off mechanism of acid secretion after duodenal acidification.