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 for mutagenicity in cultured Chinese hamster V79 cells. Mutations at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) gene locus were quantified. 1-NO2Py had marginal direct-acting mutagenicity 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 were more mutagenic than 1-NO2Py when a post-microsomal liver supernatant (S100) was used for metabolic activation. The results of these investigations strongly support activation of some nitrated polycyclic aromatic hydrocarbons to proximate mutagens by a sequence of reductions and possible formation of polycyclic aromatic hydroxylamines.