title: Enhancement of hepatic microsome-mediated bacterial mutagenesis by the rat liver soluble protein fraction.
abstract: Bacterial mutagenesis from aflatoxin B1, 2-aminofluorene and benzo[a]-pyrene, mediated by washed rat liver microsomes using the assay system of Ames, is elevated 2--4-fold by the liver soluble protein fraction. Enhancement results from an apparent stimulation of one (or possible more) biochemical steps leading to mutagenesis in this system. Enhancement is observed over a wide range of NADPH concentrations and is present in dialyzed preparations of liver soluble proteins. Enhancement activity is stable when the soluble protein fraction is stored for 18 h at pH 5-9 (4 degrees C); when stored for 18 h at 25 degrees C or 37 degrees C (pH 7.8), and when heated for 10 min at 56 degrees C. The activity is labile when heated for 10 min at 100 degrees C.
mesh_terms: D000348:Aflatoxins / Q000378:metabolism; D000818:Animals; D001580:Benzopyrenes / Q000378:metabolism; D001711:Biotransformation; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D012486:Salmonella typhimurium / Q000235:genetics
chemical_list: D000348:Aflatoxins; D001580:Benzopyrenes; D009153:Mutagens; D011506:Proteins