title: Effects of 7, 8-benzoflavone and SKF 525-A on the enzyme-mediated mutagenicity of phenylenediamines.
abstract: The effects of microsomal enzyme inhibitors (7, 8-BF and SKF 525-A) on the S-9-mediated mutagenicity of o-, m- and p-phenylenediamine were investigated using Salmonella typhimurium TA98. SKF 525-A did not affect the enzyme-mediated mutagenicity of m- and p-phenylenediamine, while 7, 8-BF reduced significantly the mutagenicity of all three isomers of phenylenediamine. When the enzyme reactions in the agar overlayer were stopped successively by adding 7, 8-BF directly onto the plate, the number of revertants increased linearly with time at least for 6 hours. These data suggest that cytochrome P-448 takes a main role in the activation of phenylenediamines and that in the agar layer this microsomal enzyme remain active for a period as long as 6 hours at 37 degrees C.
mesh_terms: D000818:Animals; D001571:Benzoflavones / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D008297:Male; D008861:Microsomes / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000037:antagonists & inhibitors; D009153:Mutagens / Q000378:metabolism*; D010655:Phenylenediamines / Q000378:metabolism / Q000633:toxicity*; D011335:Proadifen / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D001571:Benzoflavones; D005419:Flavonoids; D009153:Mutagens; D010655:Phenylenediamines; C011512:alpha-naphthoflavone; D011335:Proadifen; D006899:Mixed Function Oxygenases; C027270:cytochrome P448-dependent mono-oxygenase