Glucagon-like peptide-1 7-36 amide and peptide YY have additive inhibitory effect on gastric acid secretion in man

Background: Glucagon-like peptide-1 7-36 amide (GLP-1) and peptide YY (PYY) are colocalized in the L-cell of the ileal mucosa, and both peptides may function as enterogastrone hormones. However, it is not known whether they interact with regard to the effect on acid secretion. Methods: The effect of intravenous infusion of GLP-1 and PYY, either alone or in combination, on pentagastrin-induced acid secretion in eight healthy volunteers was examined. The peptides were infused at two different rates: 0.25 pmol/kg/min (low rate) and 0.5 pmol/kg/min (high rate). Results: Given alone, GLP-1 and PYY inhibited acid secretion by 26 +/- 5% and 18 +/- 5% (low rate) and 45 +/- 8% and 38 +/- 7% (high rate), respectively. Combined infusion resulted in an inhibition of 32 +/- 5% (low rate) and 62 +/- 7% (high rate). Both infusion rates resulted in GLP-1 and PYY plasma concentrations below or similar to postprandial levels. Conclusion: The present study suggests that the interaction between GLP-1 and PYY in man is of the additive type. The results indicate that GLP-1 and PYY have an important role in the physiologic control of gastric acid secretion.