N-Nitrosobis(2-oxopropyl)amineによるハムスター膵と肝内胆管癌発生に対するN-(4-hydroxyphenyl)retinamideの影響

Abstract

Effects of N-(4-hydroxyphenyl)retinamide (4-HPR), a synthetic retinoid, on pancreatic duct and intra-hepatic bile duct carcinogenesis were investigated using a rapid production of pancreatic duct carcinomas in hamsters and the following results were obtained. 1. No toxic signs including growth retardation and loss of pancreas and liver weights of 4-HPR were observed. 2. As pancreatic ductal lesions, duct epitherial hyperplasia, atypical hyperplasia and adenocarcinoma were histologically observed. 3. The diet containing 0.0015% 4-HPR reduced the numbers of atypical hyperplasia, adenocarcinoma and total ductal lesions. 4. The diet containing 0.01% and 0.04% 4-HPR increased the incidence and number of intra-hepatic bile duct carcinoma. These results indicate that 4-HPR possesses diverse actions inhibiting pancreatic duct carcinogenesis in low doses, and enhancing intra-hepatic bile duct carcinogenesis in high doses.