Effects of cholecystokinin (CCK)-JMV-180 on the CCK receptors of rabbit pancreatic acini and gallbladder smooth muscle.
Effects of cholecystokinin (CCK)-JMV-180, a CCK analog, on the CCK receptor functions of isolated rabbit pancreatic acini and gallbladder smooth muscle were studied. When the pancreatic acini were incubated with increasing concentrations of CCK-8, stimulation of amylase release reached a maximum at 3 nM and then declined with the increasing concentration of CCK-8. CCK-JMV-180 also caused a dose-dependent amylase release stimulation, which plateaued and remained unchanged above 300 nM at about 50% of the maximal stimulation by CCK-8. CCK-JMV-180 above 100 nM caused a rightward shift of the downstroke of the dose-response curve for CCK-8 (pA2 = 7.5). In the gallbladder smooth muscle, CCK-8 caused a dose-dependent contraction, but CCK-JMV-180 totally lacked this property. Instead, CCK-JMV-180 caused a rightward shift of the dose-response curve for CCK-8 (pA2 = 7.9). These results suggest that CCK-JMV-180 distinguishes between the CCKA receptors associated with pancreatic exocrine secretion in the acini and those involved in contraction of the isolated gallbladder smooth muscle in rabbits.
Taniguchi
H
H
Pharmacological Research Laboratory, Tanabe Seiyaku Co., Ltd., Saitama, Japan.
Nagasaki
M
M
Tamaki
H
H
D000681:Amylases / Q000378:metabolism; D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology; D005704:Gallbladder / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011817:Rabbits; D011949:Receptors, Cholecystokinin / Q000037:antagonists & inhibitors*; D012844:Sincalide / Q000031:analogs & derivatives* / Q000494:pharmacology
D007457:Iodine Radioisotopes; D011949:Receptors, Cholecystokinin; C058451:JMV 180; D002766:Cholecystokinin; D000681:Amylases; D012844:Sincalide