title: Low affinity cholecystokinin receptor inhibits cholecystokinin- and bombesin-induced oscillations of cytosolic Ca2+ concentration.
abstract: We have investigated whether low affinity cholecystokinin (CCK) receptors suppress agonist-induced rises of cytosolic free Ca(2+) concentration ([Ca(2+)]c) in pancreatic acinar cells by using properties of caffeine. A high concentration of caffeine (20 mM) completely blocked inositol 1,4,5-trisphosphate (InsP(3))-induced [Ca(2+)]c rises but spared the InsP(3)-independent long-lasting [Ca(2+)]c oscillations. In the presence of 20 mM caffeine, only high concentrations of CCK, but not bombesin or JMV-180, suppressed the caffeine-resistant CCK or bombesin-induced [Ca(2+)]c oscillations, indicating that low affinity CCK receptors inhibit agonist-induced [Ca(2+)]c oscillations. It could be one of the underlying mechanisms by which low affinity CCK receptors suppress secretion in pancreatic acinar cells.
authors.affiliation: Department of Physiology, Sungkyunkwan University School of Medicine, 300 Chunchundong, Janganku, Suwon 440-746, South Korea.
authors.forename: Kwang Kook
authors.initials: KK
authors.lastname: Lee
authors.forename: Dae-Yong
authors.initials: DY
authors.lastname: Uhm
authors.forename: Myoung Kyu
authors.initials: MK
authors.lastname: Park
mesh_terms: D000818:Animals; D001839:Bombesin / Q000037:antagonists & inhibitors* / Q000502:physiology; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002766:Cholecystokinin / Q000037:antagonists & inhibitors* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011949:Receptors, Cholecystokinin / Q000502:physiology*
chemical_list: D011949:Receptors, Cholecystokinin; D002110:Caffeine; D002766:Cholecystokinin; D001839:Bombesin; D002118:Calcium