Mutagenicity of 1-, 3- and 6-nitrosobenzo[a]pyrene in Salmonella typhimurium and Chinese hamster ovary cells

Nitrobenzo[a]pyrene‐induced DNA amplification in SV40‐transformed chinese hamster embryo cells

“…It is likely that C060 cells are capable of ring oxidation and/or nitroreduction since PAHs induce amplification in these cells without exogenous activation [Lavi and Etkin, 19811, and it has been shown that 1-, 3-, and 6-NBaP are ring-oxidized to mutagenic compounds in the presence of rat liver microsomes and S9 [Chou et al, 1985[Chou et al, , 1986Thomton-Manning et al, 19881. It has been suggested that 1-, 3-, and 6-NBaP are metabolized to corresponding nitroso-BaPs [Heflich et al, 19891 because these compounds are more mutagenic than the parent nitro-BaPs in Salmonella typhirnuvium and CHO cells Heflich et al, 1989;Thornton-Manning et al, 19891, but the capacity of C060 cells to perform nitroreduction is presently unknown.…”

A Novel Pathway to the Ultimate Mutagens of Aromatic Amino and Nitro Compounds

“…N ylamines by S9 mix may vary from compound to compound. Furthermore, it cannot be excluded that an enzyme that activates amino or nitro compounds in general still discriminates against certain specific substrates; there is some evidence for this in the case of the nitroreduction of nitrobenzopyrenes by Salmonella (10). The mutagenic activities shown in Table 1 span more than five orders of magnitude; as mentioned above, this can be considered an expression of corresponding differences in the electrophilic character of the ultimate species.…”

Molecular characterization of mutation and comparison of mutation profiles in thehprt gene of Chinese hamster ovary cells treated with benzo[a]pyrenetrans-7,8-diol-anti-9,10-epoxide, 1-nitrobenzo[a]pyrenetrans-7,8-diol-anti-9,10-epoxide, and 3-nitrobenzo[a]pyrenetrans-7,8-diol-anti-9,10-epoxide

“…Because most of the nitroPAHs so far studied are derived from nontumorigenic PAHs, ring-oxidation typically results in detoxification [Fu, 19901. We have been interested in the structure-Abbreviations: CHO, Chinese hamster ovary; BaF, benzo [a]pyrene; nitroBaP, nitrobenzo [a]pyrene; BaF-DE, trans-7,8-dihydroxy-anti-9,lO-epoxy-7,8,9,1O-teb-ahydrobenzo[a]pyrene; anti-9,10epoxy-7,8,9,1O-tetrahydro-l -nitrobenzo [a]pyrene; 3-nitro-BaF-DE, rrans-7,8-dihydroxy-anti-9,1 O-epoxy-7,8,9,1 O-tetrahydro-3-nitrobenzo[a]-pyrene; dG-BaF-DE, lO-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,1O-tetrahydrobenzo[a]pyrene; dG-l-nitro-BaP-DE, 10-(deoxyguanosin-N2-yl)- 7,8,9-trihydroxy-7,8,9, 10-tetmhydro-l-nitrobenm[a]pyrene; dG-3-nitro-BaP-DE, 1O-(deoxyguanosin-NZ-yl)-7,8,9-trihydroxy-7,8,9,1O-tetrahydro-3-nitrobenzo[a]pyrene; hprf, hypoxanthine-guanine phosphoribosyltransferase (gene); PCR, polymerase chain reaction; FBS, fetal bovine serum; DMSO, activity relationships of nitro-PAHs [Beland et al, 1985;Fu, 1990;Fu et al, 1986Fu et al, , 1988aFu et al, ,b, 1993Fu et al, , 1994Chou et al, 1984Chou et al, , 1985Chou et al, , 1986Wang et al, 1988;Jung et al, 1991;Yu et al, 1992;HerrenoSaenz et al, 19921, with a particular focus on the isomeric nitrobenzo [a]pyrenes (nitro-BaPs) that are derived from benzo [a]pyrene (BaP), the prototype for the study of PAH carcinogenesis [Yang and Silverman, 1988;Dipple et al, 1984;Osborne and Crosby, 19871. Both 1 -nitro-BaP and 3-nitro-BaP are environmental contaminants and are potent mutagens in Salmonella typhimurium TA98 in the presence and absence of rat liver S9 activation; they are also moderate mutagens in Chinese hamster ovary (CHO) cells with S9 activation [Chou et al, 1984[Chou et al, , 1985Pitts et al, 1978Pitts et al, , 1984Heflich et al, 1989;Thornton-Manning et al, 1988;…”