Inhibition of gastric and pancreatic secretions by cerebroventricular injections of gastrin-releasing peptide and bombesin in rats.
It has been suggested that mammalian gastrin-releasing peptide (GRP) and bombesin (BBS) might inhibit gastric secretion by a central nervous system action. The present investigations were intended to define the gastric effect and to look for an effect on the exocrine pancreas. Wistar male rats were provided with a chronic cannula allowing cerebroventricular injections in the 3rd ventricle, and with chronic gastric and/or pancreatic fistulas allowing the collection of gastric and/or pancreatic secretions in conscious animals. Both basal secretions were studied. Gastric secretion was stimulated with a 75 mg/kg s.c. injection of 2-deoxyglucose (2-dGlc). The dose range of bombesin was 0.01-1 microgram (6-600 pmol) and GRP was 0.01-10 microgram/rat (3.5 pmol to 3.5 nmol). A significant dose related decrease of basal gastric secretion was observed with the two peptides. The gastric acid response to 2-dGlc was inhibited by both peptides in a dose-related fashion and the reduction of gastric acid output mainly resulted from a decrease in the volume of gastric juice. The exocrine pancreatic secretion was also decreased by 30-55% after GRP but the BBS inhibitory effect was poorly dose-related. No significant difference was found after removal of gastric secretion, indicating that most of the pancreatic inhibition was independent of gastric secretion.
D000818:Animals; D001839:Bombesin / Q000008:administration & dosage / Q000494:pharmacology*; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D007276:Injections, Intraventricular; D008297:Male; D010179:Pancreas / Q000378:metabolism*; D010189:Pancreatic Juice / Q000378:metabolism; D010455:Peptides / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010455:Peptides; D019886:Gastrin-Releasing Peptide; D001839:Bombesin