title: Nitric oxide donors as generators and scavengers of superoxide anions.
abstract: Three classical direct nitric oxide (NO) donors, 3-morpholine-sydnonimine (SIN-1), S-nitroso-N-acetyl-d,l-penicillamine (SNAP) and sodium nitroprusside (NaNP) as well as two indirect NO donors, molsidomine (MSL) and glyceryl trinitrate (GTN) were studied for their potencies to generate O2-, to scavenge O2-, to consume molecular oxygen and to inhibit lipid oxidation. Out of five NO donors only those which were spontaneous releasers of NO at physiological pH were also scavengers of O2- which has been generated by xanthine:xanthine oxidase system (SIN-1 IC50 19 microM, SNAP IC50 416 microM) and inhibitors of the Fe3+ and ascorbate stimulated oxidation of rat liver lipids (SIN-1 IC50 76 microM, SNAP IC50 12 microM). Only SIN-1 at high concentrations of 300-5000 microM generated O2- as detected by a SOD inhibitable reduction of nitroblue tetrazolium. None of the in vitro studied activities were exerted by NaNP, MLS and GTN.
authors.affiliation: Department of Pharmacology, N. Copernicus Medical Academy, Kraków, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Robak
authors.forename: R J
authors.initials: RJ
authors.lastname: Gryglewski
mesh_terms: D000818:Animals; D016166:Free Radical Scavengers; D006863:Hydrogen-Ion Concentration; D015227:Lipid Peroxidation / Q000187:drug effects; D008862:Microsomes, Liver / Q000187:drug effects; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D026423:S-Nitroso-N-Acetylpenicillamine; D013481:Superoxides / Q000378:metabolism*; D019820:Xanthine; D014969:Xanthine Oxidase / Q000378:metabolism; D014970:Xanthines / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D014970:Xanthines; D013481:Superoxides; D009599:Nitroprusside; D019820:Xanthine; D009580:Nitroblue Tetrazolium; D009569:Nitric Oxide; C002385:linsidomine; D026423:S-Nitroso-N-Acetylpenicillamine; D008981:Molsidomine; D014969:Xanthine Oxidase; D010396:Penicillamine