Inhibition of Cholecystokinin Response in the Gallbladder by Dibenamine and Its Protection by Benzodiazepines

Abstract
The contractile response of the guinea-pig gallbladder to cholecystokinin (CCK) and acetylcholine (ACh) was irreversibly inhibited by 5 .times. 10-5 M dibenamine, and the dibenamine-induced inhibition in the CCK response was prevented by 10-4 M chlordiazepoxide (CDP) and diazepam (DZP), but not by 10-2 M proglumide or 10-6 M atropine. The dibenamine-induced inhibition in the ACh response was prevented by 10-6 M atropine, but not by 10-4 M CDP. These findings suggest that the binding of CCK to the CCK receptor can be inhibited by benzodiazepines.