Role of the L-arginine-nitric oxide pathway in the basal hydroxyl radical production in the striatum of awake rats as measured by brain microdialysis.
In the present study, using the microdialysis technique, we provided evidence of the existence of hydroxyl radicals (.OH) in the striatum of awake rats under physiological conditions. This .OH generation was virtually abolished by the N-methyl-D-aspartate (NMDA) receptor antagonist dizocilpine. On the contrary, it was significantly enhanced by the .NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME). The effect of L-NAME was completely reversed by L-arginine. These results suggest that the basal .OH production is largely the consequence of an NMDA receptor-mediated glutamatergic tone. Moreover, it is likely that endogenous .NO exerts an antioxidant activity in brain by preventing the rise in .OH levels.
Lancelot
E
E
Laboratoire de Pharmacologie, Université René Descartes, Paris, France.
Callebert
J
J
Lerouet
D
D
Revaud
M L
ML
Boulu
R G
RG
Plotkine
M
M
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003243:Consciousness; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000378:metabolism*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D062385:Hydroxybenzoates / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D019331:NG-Nitroarginine Methyl Ester; D017072:Neostriatum / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000975:Antioxidants; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; D062385:Hydroxybenzoates; D017665:Hydroxyl Radical; D016291:Dizocilpine Maleate; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester