Inhibition by hemin of dinitropyrene-induced mutagenesis in Chinese hamster V79 cells

The inhibitory effects of hemin on the mutagenic activities of 1,3-, 1,6- and 1,8-dinitropyrenes (1,3-,1,6- and 1,8-DNPs) were investigated in Chinese hamster V79 cells. Mutant cells were selected on the basis of their resistance to ouabain. Hemin itself did not have any cytotoxic effect on Chinese hamster V79 cells, and did not induce mutations when added at a concentration of 10 micrograms/ml. The mutagenic activities of 1,3-, 1,6- and 1,8-DNPs were inhibited dose-dependently by hemin and were reduced 91.7%, 95.7% and 94.7%, respectively, by the highest concentration of hemin tested (10 micrograms/ml).