[Carcinogenic effect of N-methyl-N-nitro-N-nitrosoguanidine on male rats of different inbred lines].

Rats reveal distinct variations in response to carcinogenic action. The highest frequency of stomach tumors (69.6%) and the shortest period of their development (54.7 weeks) were registered in noninbred rats. Multiple lesions of the gastrointestinal tract were relatively frequent, too. Augustus and Penguin rats responded with a high frequency of tumor development. However, tumors arose in them later than in noninbred rats. Wistar rats appeared to be relatively resistant to MNNG action.