Induction of DNA strand breaks by nitrosocimetidine.

The DNA of a transformed epithelial mouse cell line was studied by means of the alkaline filter elution test. Addition of N-nitrosocimetidine (NC) to the cells in vitro resulted in a concentration-dependent increase in DNA damage. In contrast cimetidine itself had no effect. The capacity of NC to generate DNA strand breaks was found to be smaller by comparison with the potent gastric carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).