title: In vitro enhancement of the mutagenicity of 4-nitro-o-phenylenediamine by plant S-9.
abstract: The direct-acting mutagen 4-nitro-o-phenylenediamine (NOP) was activated in vitro by pea or tobacco S-9 into a more potent mutagen in Salmonella typhimurium strain TA98. NOP mutagenicity was not altered by Aroclor 1254-induced rat liver S-9. The plant S-9 activation of NOP was heat-sensitive but was not NADPH-dependent, did not involve superoxide radicals, and was not inhibited by CO. A direct relationship between plant peroxidase and NOP activation was established. Several purified peroxidases including horseradish peroxidase, chloroperoxidase, and lactoperoxidase also activated NOP. The perodoxidative process was not H2O2-dependent but was partially inhibited by a peroxidase inhibitor.
mesh_terms: D000818:Animals; D001711:Biotransformation; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000201:enzymology; D008297:Male; D009152:Mutagenicity Tests; D010544:Peroxidases / Q000378:metabolism; D010655:Phenylenediamines / Q000378:metabolism* / Q000633:toxicity; D010944:Plants / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D010655:Phenylenediamines; D010544:Peroxidases; D013482:Superoxide Dismutase