Potent mutagenic activity of nitropyrenes on Chinese hamster lung cells with diphtheria toxin resistance as a selective marker.

Nitropyrenes, which are highly mutagenic in the Salmonella assay, were shown also to be potent mutagens on Chinese hamster lung cells without metabolic activation when resistance to diphtheria toxin was used as a selective marker. Among nitropyrenes tested, 1,8- and 1,6-dinitropyrenes were the most mutagenic, and 1,3-dinitro- and 1,3,6-trinitropyrenes were less active, but showed still much higher mutagenic activity than methyl methanesulfonate or N-methyl-N-nitrosourea. 1-Nitropyrene and 1,3,6,8-tetranitropyrene did not induce diphtheria toxin-resistant mutants at concentrations of up to 20 micrograms/ml.