1989 Volume 38 Issue 11 Pages T174-T178
A fluorometric HPLC method for the determination of valproic acid (VPA) in mouse brain was developed using 3- bromomethyl-6, 7-dimethoxy- 1-methyl-2 (1H) -quinoxalinone(Br-DMEQ) as a prelabelling reagent. The method was used to study the interrelations among the concentrations of VPA, γ-aminobutyrate as an inhibitory amino acid and glutamate or aspartate as an excitatory amino acid in mouse brain. The brain levels of VPA decreased with a half life of 0.99 h and attained almost zero at 5 h after the intraperitoneal administration of VPA at a dose of 200 mg/kg to mice. The administration of VPA gave rise to a significant increase in γ-aminobutyrate in response to a significant decrease in aspartate and glutamate in mouse brain. In particular, aspartate continued to decrease up to 8 h after administration whereas VPA disappeared at 5 h. The present observations are considered closely correlated to the “carried over effect” of VPA.
