title: Mutagenicity of nitroxide-free radicals.
abstract: Stable nitroxides were found to be mutagenic using Salmonella typhimurium tester strain TA 104, a strain chosen on the basis of its high sensitivity to oxidative damage. Nitroxide mutagenicity was dramatically increased in the presence of the superoxide radical generating system, xanthine oxidase/hypoxanthine, and it was suppressed in cells carrying the oxyR1 mutation, which causes induction of enzymes protecting against oxidative stress. As nitroxide-free radicals occur biologically, e.g., in the metabolism of aromatic amines, these radical-induced mutations could be a model for the carcinogenicity observed with these compounds.
mesh_terms: D003497:Cyclic N-Oxides / Q000633:toxicity*; D005609:Free Radicals; D009152:Mutagenicity Tests; D009153:Mutagens; D011758:Pyrroles; D011759:Pyrrolidines; D012486:Salmonella typhimurium / Q000187:drug effects; D013113:Spin Labels; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D003497:Cyclic N-Oxides; D005609:Free Radicals; D009153:Mutagens; D011758:Pyrroles; D011759:Pyrrolidines; D013113:Spin Labels; C050260:3-hydroxymethyl-2,2,5,5-tetramethylpyrroline-N-oxyl; D014969:Xanthine Oxidase; C001803:tempol