title: In vitro effect of different ubiquinones on the scavenging of biologically generated O2-.
abstract: The ability of different homologues of Coenzyme Q to quench O2- was tested in vitro with three experimental systems known to generate O2-. Two of them were biological generators, namely the xanthine-xanthine oxidase system and the cyanide-insensitive NADPH oxidase of polymorphonuclear leucocytes. The third was a chemical generator of O2-, the NADH-phenazine methosulphate-nitroblue tetrazolium mixture. Short-side-chain ubiquinones were found to be the most potent scavengers of O2-, being effective at concentrations as low as 10(-7) M. This finding might be ascribed to the relatively greater water-solubility of the lower homologues of CoQ. We postulate that CoQ10 may well exert such an O2- -scavenging mechanisms in vivo where it is inserted in its natural phospholipid environment.
mesh_terms: D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008773:Methylphenazonium Methosulfate; D009243:NAD; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D019255:NADPH Oxidases; D009504:Neutrophils / Q000378:metabolism; D009580:Nitroblue Tetrazolium; D013481:Superoxides / Q000378:metabolism*; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000378:metabolism; D014970:Xanthines / Q000378:metabolism
chemical_list: D014970:Xanthines; D009243:NAD; D013481:Superoxides; D014451:Ubiquinone; D009580:Nitroblue Tetrazolium; D008773:Methylphenazonium Methosulfate; D014969:Xanthine Oxidase; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases