Effect of di-isopropanolnitrosamine in European hamsters.

The carcinogenic effects of di-isopropanolnitrosamine (DIPN) were tested in hibernating and non-hibernating European hamsters. The results obtained were compared with those produced by the same substance in Syrian golden hamsters and Sprague-Dawley rats. In European hamsters, tumours were produced in the nasal cavity, trachea, lung, liver and pancreas. The main target organs were the anterior part of the nasal cavity and liver. Only cholangiomas and cholangiocarcinomas were found in the liver. Early changes in the intrahepatic bile ducts and duct epithelium of the pancreas were seen 4 weeks after treatment was started. Fourteen out of 144 treated hamsters developed pancreatic-duct tumours, 2 of which were malignant. The tumorigenic response in the target organs was lower in hibernating than in non-hibernating animals.