Enhancement of biliary carcinogenesis in hamsters by cholecystokinin.

We recently developed a new model for rapid and reproducible induction of biliary carcinoma in hamsters. In the present study, we evaluated the effects of cholecystokinin (CCK), which has a trophic action on the gastrointestinal tract and on the pancreaticobiliary system, on biliary carcinogenesis in this hamster model. Hamsters treated with N-nitrosobis (2-oxopropyl) amine (BOP) were divided into four groups: In Group I, hydrolyzed gelatin, a solvent of CCK, was injected subcutaneously. In Groups II and III, CCK 2.5 and 25 microgram/kg were administered, respectively. In Group IV loxiglumide, a CCK receptor antagonist, was administered. CCK significantly promoted the carcinogenetic effect of BOP in the intra- and extrahepatic bile ducts but not in the gallbladder or pancreas. Loxiglumide exerted an inhibitory effect on carcinogenesis in the intrahepatic bile duct.