Contrasting carcinogenic effects of nitroso-2,6-dimethylmorpholine given by gavage to F344 rats and Syrian golden hamsters.

Nitroso-2,6-dimethylmorpholine (Me2NM) has been given by gavage to F344 rats of both sexes and to male Syrian hamsters at similar doses. The rats died more rapidly from the tumors induced than did the hamsters, the males being more susceptible than the females. The rats developed mainly carcinomas and papillomas of the esophagus, whereas the hamsters died with angiosarcomas of the liver, ductal adenocarcinomas of the pancreas, adenocarcinomas of the lung and olfactory adenocarcinomas of the nasal cavity. It was notable that, with the exception of a few lung tumors in the rat, none of the tumors found in the hamster were induced by Me2NM in the rat, and no esophageal tumors were seen in the hamsters.