Gastric Acid Response to Pentagastrin and Gastrin-Releasing Peptide in Conscious Cats

The mammalian counterpart to bombesin, gastrin-releasing peptide (GRP), is considered to stimulate gastric acid secretion by release of endogenous gastrin. The present study was carried out to examine if GRP has a stimulatory action on acid secretion in addition to that produced by released gastrin. In 4 gastric fistula (GF) and Heidenhain pouch (HP) cats, 160 pmol X kg-1 X h-1 i.v. GRP produced a GF and HP acid response that amounted to 22 and 13%, respectively, of the maximal acid response to pentagastrin, with no rise in serum gastrin concentration. GRP significantly increased the maximal acid response to pentagastrin in the GF but not in the HP. These results suggest that GRP stimulates acid secretion in cats also by an action not related to the release of gastrin. This action is greater in the presence of vagal innervation.