THE INHIBITORY EFFECT OF GLUCAGON-LIKE PEPTIDE-1 (GLP-1) 7-36-AMIDE ON GASTRIC-ACID SECRETION IN HUMANS DEPENDS ON AN INTACT VAGAL INNERVATION

Background-Glucagon-like peptide-1 (GLP-1)(7-36) amide is an intestina l incretin hormone which also inhibits gastric acid secretion in human s. Its mechanism of action is unclear, but it strongly inhibits vagall y induced secretion (sham feeding), suggesting that it could influence vagal activity. Aim/Methods-The effect of intravenous GLP-1 (7-36 ami de) (1 pmol/kg/min) was studied on pentagastrin induced acid secretion in otherwise healthy subjects, previously vagotomised for duodenal ul cer (n=8) and in a group of young (n=8) and old (n=6) healthy voluntee rs. Results-Pentagastrin increased acid secretion significantly in all three groups, but the plateau concentration in the vagotomised subjec ts was lower than in controls. Infusion of GLP-1 (7-36 amide) signific antly inhibited acid secretion in the control groups (to 67 (SEM 6) an d 74 (SEM 3)% of plateau concentrations in young and old controls, res pectively) but had no effect in the vagotomised subjects. Differences in plasma concentrations of vagotomy. GLP-1 (7-36 amide), recovery of gastric marker, duodenal regurgitation, or Helicobacter pylori status could not explain the Methods lack of effect. Blood glucose was lowere d equally by GLP-1 (7-36 amide) in all subjects subjects. Conclusion-T he inhibitory effect of GLP-1 (7-36 amide) on acid secretion depends o n intact vagal innervation of the stomach.