Determination of kynurenic acid levels in rat brain microdialysis samples and changes in kynurenic acid levels induced by N-acetylaspartic acid.
The levels of kynurenic acid, an endogenous antagonist of alpha(7) nicotinic acetylcholine and N-methyl-D-aspartate receptors, were measured in microdialysis samples obtained from the prefrontal cortices of rats using column-switching high-performance liquid chromatography with fluorescence detection. When the perfusate was constantly infused at a rate of 1.0 mu/min, the in vitro recovery of kynurenic acid through the dialysis membrane was approximately 20.4%, and the precision was within 1.31%. Endogenous kynurenic acid in the microdialysis sample was clearly detected using column-switching high-performance liquid chromatography. As an application study, N-acetyl-L-aspartic acid, an endogenous metabolite and precursor of N-acetyl-L-aspartyl-L-glutamic acid, which is an agonist of metabotropic glutamate receptors, was infused for 120 min through the microdialysis probe. The kynurenic acid level significantly increased during the infusion of N-acetyl-L-aspartic acid, suggesting that kynurenic acid might have some association with N-acetyl-L-aspartic acid in vivo.
Tomiya
Masayuki
M
Division of Bio-Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
Fukushima
Takeshi
T
Ogaya
Tadahiro
T
Sone
Yukiko
Y
Mitsuhashi
Shogo
S
Toyo'oka
Toshimasa
T
D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000032:analysis; D001923:Brain Chemistry; D007736:Kynurenic Acid / Q000032:analysis*; D008297:Male; D017551:Microdialysis / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley
D001224:Aspartic Acid; C000179:N-acetylaspartate; D007736:Kynurenic Acid