Determination of GABA Glutamate and Carbamathione in Brain Microdialysis Samples by Capillary Electrophoresis with Fluorescence Detection

摘要

Disulfiram has been used as a deterrent in the treatment of alcohol abuse for almost 60 years. Our laboratory has shown that a disulfiram metabolite, S-(N, N-diethylcarbamoyl) glutathione (carbamathione) is formed from disulfiram and appears in the brain after the administration of disulfiram. Carbamathione does not inhibit ALDH2 but has been shown to be a partial non-competitive inhibitor of the N-methyl-D-aspartic acid (NMDA) glutamate receptor In light of disulfiram’s apparent clinical effectiveness in cocaine dependence, and carbamathione’s effect on the NMDA receptor, the effect of carbamathione on brain glutamate (Glu) and γ-aminobutyric acid (GABA) needed to be further examined. A CE-LIF method based on derivatization with napthalene-2,3-dicarboxyaldehyde (NDA) to simultaneously detect both neurotransmitter amino acids and carbamathione in brain microdialysis samples is described. The separation of Glu, GABA and carbamathione was carried out using a 50 mmol/L boric acid buffer (pH 9.6) on a 75 cm × 50 μm id fused-silica capillary (60 cm effective) at + 27.5 kV voltage with a run time of 11 min. The detection limits for Glu, GABA and carbamathione were 6, 10 and 15 nmol/L, respectively. This method was used to monitor carbamathione and the amino acid neurotransmitters in brain microdialysis samples from the nucleus accumbens after the administration of an intravenous dose of the drug (200 mg/kg) and revealed a carbamathione-induced change in GABA and Glu levels. This method demonstrates a simple, rapid and accurate measurement of two amino acid neurotransmitters and carbamathione for in vivo monitoring in the brain using microdialysis sampling.