title: Are quinones producers or scavengers of superoxide ion in cells?
abstract: The effects of quinones (benzoquinone, menadione, and doxorubicin) on the superoxide production in cell free systems (xanthine oxidase and rat liver microsomes) and of polycationic electrolyte- and latex-stimulated rat peritoneal macrophages have been studied. Contradictory results were obtained in cell free systems when two traditional assays for detection of superoxide ion, the cytochrome c reduction and the lucigenin-dependent chemiluminescence (CL), were used: all quinones inhibited the lucigenin-dependent CL at sufficiently large concentrations, but they did not inhibit at all the reduction of cytochrome c. It was proposed that the cytochrome c assay gave erroneous results due to the reversibility of the interaction of semiquinones with dioxygen. The effect of quinones on the superoxide production by peritoneal macrophages was biphasic: all quinones stimulated the O2-. formation at low concentrations and inhibited it at elevated concentrations. It was concluded that among the quinones studied, only menadione was capable of stimulating the superoxide production via a one-electron transfer mechanism in cell free systems, while the stimulatory effect of small concentrations of quinones on the O2-. production in macrophages was possibly due to their action on the activation of NADPH oxidase.
authors.affiliation: All Union Vitamin Research Institute, Moscow, USSR.
authors.forename: I B
authors.initials: IB
authors.lastname: Afanas'ev
authors.forename: L G
authors.initials: LG
authors.lastname: Korkina
authors.forename: T B
authors.initials: TB
authors.lastname: Suslova
authors.forename: S K
authors.initials: SK
authors.lastname: Soodaeva
mesh_terms: D000818:Animals; D016227:Benzoquinones; D002474:Cell-Free System; D003574:Cytochrome c Group / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D008163:Luminescent Measurements; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009580:Nitroblue Tetrazolium; D010084:Oxidation-Reduction; D011809:Quinones / Q000494:pharmacology*; D051381:Rats; D013481:Superoxides / Q000378:metabolism*; D014812:Vitamin K / Q000494:pharmacology*; D014969:Xanthine Oxidase / Q000378:metabolism; D014970:Xanthines / Q000378:metabolism
chemical_list: D016227:Benzoquinones; D003574:Cytochrome c Group; D011809:Quinones; D014970:Xanthines; D013481:Superoxides; D014812:Vitamin K; D009580:Nitroblue Tetrazolium; C004532:quinone; D004317:Doxorubicin; D014969:Xanthine Oxidase