title: Activation of mutagens in cooked ground beef by human-liver microsomes.
abstract: The total organic base fraction purified from fried ground beef is metabolized by human-liver microsomes to form mutagens detectable by the Ames/Salmonella bacterial assay. The mutagens produced have an absolute requirement for metabolic activation; without it, no increase in the number of revertants over background is seen. Microsomes from human liver activate the mutagens significantly more than microsomes from uninduced mouse or rat liver; the microsomes from one individual were nearly as active as those of Aroclor-induced mice and rats. alpha-Naphthoflavone (ANF) inhibits activation of these mutagenic bases, implying that the metabolism is mediated by the inducible form(s) of cytochrome P-448. Thus, the human liver has the potential to metabolize the cooked beef mutagen(s) to active intermediates, posing a possible mutagenic risk. However, unlike the animal metabolizing system, which needs to be artificially induced, the human system appears to be naturally induced through diet or environmental exposure.
mesh_terms: D000818:Animals; D001140:Aroclors / Q000494:pharmacology; D001711:Biotransformation; D002417:Cattle; D020111:Chlorodiphenyl (54% Chlorine); D003296:Cooking; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008460:Meat / Q000032:analysis*; D051379:Mice; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D009152:Mutagenicity Tests; D009153:Mutagens / Q000302:isolation & purification* / Q000633:toxicity; D009154:Mutation; D051381:Rats; D011919:Rats, Inbred Strains; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D001140:Aroclors; D009153:Mutagens; D020111:Chlorodiphenyl (54% Chlorine)