Nitric oxide, superoxide and peroxynitrite: putative mediators of NMDA-induced cell death in cerebellar granule cells.
In this study, we analysed the implication of superoxide (O2-.) and nitric oxide (NO.) free radicals and their resulting product peroxynitrite (ONOO-) in the neuronal death induced by the activation of the glutamatergic receptor of the N-methyl-D-aspartate (NMDA) subtype using cultured cerebellar granule cells. The NOl donor SIN-1 (3-morpholinosydnonimine N-ethylcarbamide), at concentrations which produced a much higher guanylate cyclase activation (i.e. NO. concentration) than NMDA, was not neurotoxic and did not increase the NMDA-induced neuronal death. The absence of involvement of NO. in NMDA-induced neuronal death was confirmed by the ineffectiveness of L-NG-nitroarginine (L-Narg) as a neuroprotective compound. Electron paramagnetic resonance (EPR) experiments, using 5,5-dimethyl pyrroline 1-oxide (DMPO) as a spin trap, indicated that NMDA receptor stimulation led to the generation of O2-. from at least 15-30 min. The generation of O2-. by xanthine (XA)-xanthine oxidase (XO) induced a neuronal death similar to that of NMDA. XA-XO-induced neuronal death was suppressed by addition of either superoxide dismutase (SOD) plus catalase (CAT), or DMPO in the incubation medium. In contrast, NMDA-induced neuronal death was widely blocked by DMPO and other spin trap compounds, but not by SOD +/- CAT. XA-XO-induced neuronal death was not potentiated by SIN-1 indicating that ONOO- is not more toxic than O2-. in our neuronal model.
Lafon-Cazal
M
M
CNRS UPR 9023, Montpellier, France.
Culcasi
M
M
Gaven
F
F
Pietri
S
S
Bockaert
J
J
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology* / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D051379:Mice; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology*; D009566:Nitrates / Q000494:pharmacology*; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology*; D014969:Xanthine Oxidase / Q000378:metabolism
D003497:Cyclic N-Oxides; D009566:Nitrates; D016194:Receptors, N-Methyl-D-Aspartate; D013481:Superoxides; D019335:Nitroarginine; C039642:peroxynitric acid; D009569:Nitric Oxide; C002385:linsidomine; D016202:N-Methylaspartate; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D001120:Arginine; D008981:Molsidomine; D002374:Catalase; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D000594:Amino Acid Oxidoreductases; D006152:Cyclic GMP