A novel in vivo assay system for consecutive measurement of brain nitric oxide production combined with the microdialysis technique.
A novel spectrophotometric nitrite (NO2-)/nitrate (NO3-) assay system for a small quantity (5 microliter) of dialysate sample obtained by in vivo brain microdialysis was developed based on the diazotization reaction. The system has the advantage of in vivo consecutive measurement, high precision, good reproducibility, technical simplicity, relatively short resolution time (2.5-20 min), and wide availability. The NO3- level in the rat striatum was found to be 3 times higher than the NO2- level. A nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester, reduced striatal NO2-/citrulline formation in a dose-related manner and increased arginine, indicating that the tissue NO2- level detected by this assay system adequately reflects the striatal NO synthase activity.
Ohta
K
K
Department of Neurology, Keio University School of Medicine, Tokyo, Japan.
Araki
N
N
Shibata
M
M
Hamada
J
J
Komatsumoto
S
S
Shimazu
K
K
Fukuuchi
Y
Y
D000594:Amino Acid Oxidoreductases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology; D001921:Brain / Q000378:metabolism*; D002956:Citrulline / Q000032:analysis / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D019331:NG-Nitroarginine Methyl Ester; D017072:Neostriatum / Q000737:chemistry / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D051381:Rats; D017207:Rats, Sprague-Dawley
D002956:Citrulline; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D019331:NG-Nitroarginine Methyl Ester