Mutagenicity of nitrofluoranthenes, 3-aminofluoranthene and 1-nitropyrene in Chinese hamster V79 cells

1-Nitropyrene (1-NO₂Py), 3-nitrofluoranthene (3-NO₂Ft), 3-aminofluoranthene(3-NH₂Ft) and 8-nitrofluoranthene (8-NO₂Ft) were tested formutagenicity in cultured Chinese hamster V79 cells. Mutationsat the hypoxanthine-guanine phosphoribosyl transferase (HGPRT)gene locus were quantified. 1-NO₂Py had marginal direct-actingmutagenicity which was enhanced by a mixture of Aroclor 1254-and 1242-induced liver homogenates (S9) in the treatment medium.1-NO₂Py was more mutagenic with S9 activation than 3-NO₂Ft,3-NH₂Ft or 8-NO₂Ft. However, 8-NO₂Ft, 3-NO₂Ft and 3-NH₂Ft weremore mutagenic than 1-NO₂Py when a post-microsomal liver supernatant(S100) was used for metabolic activation. The results of theseinvestigations strongly support activation of some nitratedpolycyclic aromatic hydrocarbons to proximate mutagens by asequence of reductions and possible formation of polycyclicaromatic hydroxylamines.