Simultaneous Determination of Biogenic Monoamines in Rat Brain Dialysates Using Capillary High-Performance Liquid Chromatography with Photoluminescence Following Electron Transfer

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• 作者：Moon Chul Jung ; Guoyue Shi ; Laura Borland ; Adrian C. Michael ; and Stephen G. Weber
• 刊名：Analytical Chemistry
• 出版年：2006
• 出版时间：March 15, 2006
• 年：2006
• 卷：78
• 期：6
• 页码：1755 - 1760
• 全文大小：96K
• 年卷期：v.78,no.6(March 15, 2006)
• ISSN：1520-6882

文摘

Simultaneous determination of biogenic monoaminessuch as dopamine, serotonin, and 3-methoxytyramine inbrain is important in understanding neurotransmitteractivity. This study presents a sensitive determination ofbiogenic monoamines in rat brain striatum microdialysates using capillary high-performance liquid chromatography with the photoluminescence following electron-transfer detection technique. Separation conditions wereoptimized by changing the concentration of an ion-interaction agent and the percentage of an organic modifier. Thehigh concentration of ion-interaction agent enabled theamines as a class to be separated from interfering acids,but also made the separation very long. To shorten theseparation time, 10% (v/v) acetonitrile was used as theorganic modifier. Eight chromatographic runs during a3-h period were analyzed in terms of retention times, peakheights, and peak widths. Chromatograms are very reproducible, with less than 1% changes in peak height over3 h. Typical concentration detection limits at the optimumseparation conditions were less than 100 pM for metabolic acids and ~200 pM for monoamines. The injectionvolume of the sample was 500 nL. Thus, the massdetection limits were less than 50 amol for metabolicacids and ~100 amol for monoamines. Typical separationtime was less than 10 min. To validate the technique, theseparation method was applied to the observation of drug-induced changes of monoamine concentrations in ratbrain microdialysis samples. Local perfusion of tetrodotoxin, a sodium channel blocker, into the striatum of ananesthetized rat decreased dopamine, 3-methoxytyramine,and serotonin concentrations in dialysates. Successivemonitoring of striatal dialysates at a temporal resolutionof 7.7 min showed that the injection of nomifensinetransiently increased dopamine and 3-methoxytyramineconcentrations in rat brain dialysate.