GASTRIN-RELEASING PEPTIDE AND CHOLECYSTOKININ IN THE REGULATION OF EXOCRINE PANCREATIC-SECRETION IN DOGS

Exocrine pancreatic secretion in conscious dogs is significantly stimu lated bv the intravenous application of small doses of gastrin-releasi ng peptide (GRP; 30 pmol X kg-1 X h-1). There is no increase of the GR P concentrations in peripheral blood which is also the case under phys iological postprandial conditions. There is also no increase in the pe ripheral cholecystokinin (CCK) concentrations, in contrast to previous reports. Nevertheless other CCK-related mechanisms may play an import ant role, since the administration of the highly specific CCK receptor antagonist MK-329 causes a marked reduction of the GRP-induced exocri ne panceratic secretion.