Carcinogenic effects of different nitroso-compounds in Chinese hamsters. I. Dimethylnitrosamine and N-diethylnitrosamine.

Three hundred and twenty Chinese hamsters (Cricetulus griseus) (CH) were treated (s.c.) with 1/5, 1/10 or 1/20 LD50 of dimethylnitrosamine (DMN) or N-diethylnitrosamine (DEN). These substances, in several respects, showed a different organotropy in this species than in both the Syrian golden (SGH) and the European hamster (EH). In CH, DEN produced up to 100% squamous cell papillomata and occasionally also carcinomata of the cheek pouch, tongue, pharynix, oesophagus and forestomach. With DEN a high rate of hepatomata was simultaneously realized. DMN induced a considerable quantity of liver tumours, the highest incidence being demonstrated in the lowest dosage group.