Species differences in nitrosamine carcinogenesis.

The carcinogenic action of approximately 50 N-nitroso compounds, nitrosamines, and nitrosoalkylamides has been compared in rats and in Syrian golden hamsters. The compounds were administered PO, as far as possible at comparable dose rates. The relative potencies of the treatments were assessed mainly by the time to death of the animals with tumors. The esophagus and other parts of the upper gastrointestinal tract were the most common sites for tumor induction in rats, but the esophagus was hardly ever affected in hamsters, although several compounds induced tumors of the forestomach in both rats and hamsters. No conclusion could be drawn about the relative susceptibility of the rat and hamster to these N-nitroso compounds, which varied with different compounds. Few generalizations can be made about these results, although it appeared that the 2-hydroxypropyl group was usually necessary for the induction of pancreas tumors in hamsters.