The gastric acid secretagogue gastrin-releasing peptide and the inhibitor oxyntomodulin do not exert their effect directly on the parietal cell in the rat.
Previous studies suggested that gastrin-releasing peptide (a neuropeptide found in rat oxyntic mucosa) and oxyntomodulin (a glucagon-containing peptide of mammalian gut) could directly affect the acid secretion of the parietal cells. We therefore studied their effect on gastric acid production in vitro by measuring [14C]-aminopyrine accumulation, a reliable index of H+ generation, in isolated rat parietal cells. However, neither gastrin-releasing peptide nor oxyntomodulin influenced basal acid secretion or histamine-stimulated gastric acid secretion. Electron-microscopic studies of unstimulated and histamine-stimulated parietal cells confirmed that the cells retained the normal morphology of intracellular organelles and that the cells responded to physiological stimulation by marked expansion of the intracellular canaliculi.
Gehl
J
J
Institute of Medical Physiology C, Panum Institute, University of Copenhagen, Denmark.
Jeppesen
J L
JL
Poulsen
S S
SS
Holst
J J
JJ
D000632:Aminopyrine / Q000378:metabolism; D000818:Animals; D005744:Gastric Acid / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D005755:Gastrins / Q000494:pharmacology*; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D053771:Glicentin; D005934:Glucagon / Q000494:pharmacology; D004763:Glucagon-Like Peptides / Q000494:pharmacology*; D006632:Histamine / Q000494:pharmacology; D008854:Microscopy, Electron; D053772:Oxyntomodulin; D010295:Parietal Cells, Gastric / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D011498:Protein Precursors / Q000494:pharmacology; D051381:Rats
D005755:Gastrins; D005768:Gastrointestinal Hormones; D053772:Oxyntomodulin; D010446:Peptide Fragments; D010455:Peptides; D011498:Protein Precursors; D000632:Aminopyrine; D004763:Glucagon-Like Peptides; D053771:Glicentin; D019886:Gastrin-Releasing Peptide; D006632:Histamine; D005934:Glucagon