title: Peroxynitrite- and nitrite-induced oxidation of dopamine: implications for nitric oxide in dopaminergic cell loss.
abstract: Increased nitric oxide (NO) production has been implicated in many examples of neuronal injury such as the selective neurotoxicity of methamphetamine and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine to dopaminergic cells, presumably through the generation of the potent oxidant peroxynitrite (ONOO). Dopamine (DA) is a reactive molecule that, when oxidized to DA quinone, can bind to and inactivate proteins through the sulfhydryl group of the amino acid cysteine. In this study, we sought to determine if ONOO could oxidize DA and participate in this process of protein modification. We measured the oxidation of the catecholamine by following the binding of [3H]DA to the sulfhydryl-rich protein alcohol dehydrogenase. Results showed that ONOO oxidized DA in a concentration- and pH-dependent manner. We confirmed that the resulting DA-protein conjugates were predominantly 5-cysteinyl-DA residues. In addition, it was observed that ONOO decomposition products such as nitrite were also effective at oxidizing DA. These data suggest that the generation of NO and subsequent formation of ONOO or nitrite may contribute to the selective vulnerability of dopaminergic neurons through the oxidation of DA and modification of protein.
authors.affiliation: Department of Neuroscience, University of Pittsburgh, Pennsylvania 15261, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: LaVoie
authors.forename: T G
authors.initials: TG
authors.lastname: Hastings
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D000426:Alcohol Dehydrogenase / Q000378:metabolism; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis; D002374:Catalase / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008694:Methamphetamine / Q000494:pharmacology; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009566:Nitrates / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010300:Parkinson Disease / Q000378:metabolism; D011485:Protein Binding; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D009419:Nerve Tissue Proteins; D009566:Nitrates; D009573:Nitrites; D016877:Oxidants; D013438:Sulfhydryl Compounds; C039642:peroxynitric acid; D009569:Nitric Oxide; D008694:Methamphetamine; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D000426:Alcohol Dehydrogenase; D002374:Catalase; D014442:Monophenol Monooxygenase; D013482:Superoxide Dismutase; D004298:Dopamine