title: Effect of peroxynitrite on the mitochondrial respiratory chain: differential susceptibility of neurones and astrocytes in primary culture.
abstract: The effect of the neurotoxic nitric oxide derivative, the peroxynitrite anion (ONOO-), on the activity of the mitochondrial respiratory chain complexes in cultured neurones and astrocytes was studied. A single exposure of the neurones to ONOO- (initial concentrations of 0.01-2.0 mM) caused, after a subsequent 24-h incubation, a dose-dependent decrease in succinate-cytochrome c reductase (60% at 0.5 mM) and in cytochrome c oxidase (52% at 0.5 mM) activities. NADH-ubiquinone-1 reductase was unaffected. In astrocytes, the activity of the mitochondrial complexes was not affected up to 2 mM ONOO-. Citrate synthase was unaffected in both cell types under all conditions studied. However, lactate dehydrogenase activity released to the culture medium was increased by ONOO- in a dose-dependent manner (40% at 0.5 mM ONOO-) from the neurones but not from the astrocytes. Neuronal glutathione concentration decreased by 39% at 0.1 mM ONOO-, but astrocytic glutathione was not affected up to 2 mM ONOO-. In isolated brain mitochondria, only succinate-cytochrome c reductase activity was affected (22% decrease at 1 mM ONOO-). We conclude that the acute exposure of ONOO- selectively damages neurones, whereas astrocytes remain unaffected. Intracellular glutathione appears to be an important factor for ameliorating ONOO(-)-mediated mitochondrial damage. This study supports the hypothesis that the neurotoxicity of nitric oxide is mediated through mitochondrial dysfunction.
authors.affiliation: Department of Neurochemistry, Institute of Neurology, London, England.
authors.forename: J P
authors.initials: JP
authors.lastname: Bolaños
authors.forename: S J
authors.initials: SJ
authors.lastname: Heales
authors.forename: J M
authors.initials: JM
authors.lastname: Land
authors.forename: J B
authors.initials: JB
authors.lastname: Clark
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects* / Q000648:ultrastructure; D001921:Brain / Q000648:ultrastructure; D002478:Cells, Cultured; D002950:Citrate (si)-Synthase / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects*; D042967:Electron Transport Complex I; D003576:Electron Transport Complex IV / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D009566:Nitrates / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013384:Succinate Cytochrome c Oxidoreductase / Q000378:metabolism
chemical_list: D009566:Nitrates; C039642:peroxynitric acid; D013384:Succinate Cytochrome c Oxidoreductase; D007770:L-Lactate Dehydrogenase; D009247:NADH, NADPH Oxidoreductases; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D042967:Electron Transport Complex I; D005978:Glutathione