Diffusion coefficients and half-lives of nitric oxide and N-nitroso-L-arginine in rat cortex.
In vivo voltammetry was performed in rat brain cortex and in rat brain endothelial constitutive NO-synthase preparations. The use of a recent microcaptor detecting N-hydroxy- and N-nitroso-L-arginine permitted to find only the latest in biological preparations. The construction of a new membrane selective electrode for nitric oxide (NO) allowed to assert its absence in these preparations at micromolar level. Half-live of N-nitroso-L-arginine was 4 s in rat brain cortex and the washout curve of NO after over brain insufflation gave an half-life of 10.5 min; their diffusion coefficients in brain were 3.810(-5) for NO and 3.910(-6) cm2.s-1 for N-nitroso-L-arginine. These facts indicate that N-nitroso-L-arginine is degraded directly into nitrites and citrulline after its synthesis by endothelial NO-synthase.
Meulemans
A
A
Faculté de médecine Xavier Bichat, Laboratoire de biophysique, Paris, France.
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D002540:Cerebral Cortex / Q000201:enzymology / Q000378:metabolism*; D004058:Diffusion; D006207:Half-Life; D008297:Male; D008839:Microelectrodes; D009569:Nitric Oxide / Q000493:pharmacokinetics*; D019001:Nitric Oxide Synthase; D009603:Nitroso Compounds / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
D009603:Nitroso Compounds; C084185:N-nitrosoarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases