Cholecystokinin (CCK)-induced desensitization of pancreatic enzyme secretion is mediated by low affinity CCK receptors.
CCK-8-induced desensitization of carbachol-stimulated amylase secretion occurred over a range of concentrations of CCK-8 that occupy low affinity CCK receptors. CCK-JMV-180 [BOC-Tyr(SO3)-Nle-Gly-Trp-Nle-Asp-2-phenylethylester] at concentrations up to 1 microM did not cause desensitization of enzyme secretion; however, the peptide was able to inhibit CCK-8-induced desensitization. Analysis of the relationship between receptor occupation and CCK-8-induced desensitization caused by CCK-8 and CCK-JMV-180 in combination also indicated that CCK-8-induced desensitization of carbachol-stimulated amylase secretion is caused by occupation of low affinity CCK receptors.
Menozzi
D
D
Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892.
Stark
H A
HA
Martinez
J
J
Jensen
R T
RT
Gardner
J D
JD
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D011949:Receptors, Cholecystokinin / Q000502:physiology*; D012844:Sincalide / Q000378:metabolism / Q000494:pharmacology*
D011949:Receptors, Cholecystokinin; D002217:Carbachol; D000681:Amylases; D012844:Sincalide