掺铂/聚3-甲基噻吩修饰电极研究氨酪酸对大鼠脑纹状体中单胺类神经递质影响

Study on the Monoamine Neurotransmitters Change in Rat Striatum Caused by γ-Aminobutyric Acid Using Liquid Chromatography Coupled with Pt/Poly-3-methylthiophene Modified Electrode

氨酪酸(GABA)是哺乳动物中枢神经系统中重要的抑制性神经递质。本研究探讨了外源性GABA对单胺类神经递质及其代谢产物的影响。研制了一种新型掺铂/聚3-甲基噻吩玻碳修饰电极,利用原子力显微镜(AFM)对该电极进行了表征,通过循环伏安法(CV)和微分脉冲伏安法(DPV)研究了单胺类神经递质及其代谢产物在该修饰电极上的电化学行为,结果表明:该修饰电极对单胺类神经递质及其代谢产物有显著的催化作用,电极的灵敏度高,稳定性和重现性好。在液相色谱电化学检测实验中,去甲肾上腺素(NE)、多巴胺(DA)、3,4-二羟基苯乙酸(DOPAC)、5-羟色胺(5-HT)和5-羟吲哚乙酸(5-HIAA)在修饰电极上的电流响应灵敏。5种被测物的检测线性范围宽达3个数量级以上,检出限分别为2.0×10-10mol/L(NE)、1.0×10-10mol/L(DA)、3.0×10-10mol/L(DOPAC)、4.0×10-10mol/L(5-HT)和7.0×10-10mol/L(5-HIAA)。将该方法与微渗析活体取样技术联用,研究了GABA对大鼠脑纹状体中单胺类神经递质及其代谢产物的影响。

γ-Aminobutyric acid（GABA） is the major inhibitory neurotransmitter in the nervous system. To study its effect on monoamine neurotransmitters and their metabolites, a novel Pt/poly-3-methyhhiophene chemically modified electrode （Pt/P3MT/CME） was developed. The Pt/P3MT/CME was characterized by atomic force microscope（AFM）. The electrochemical behaviors of monoamine neurotransmitters and their metabolites at the CME were investigated by cyclic vohammetry （CV） and differential pulse vohammetry （DPV）. The results showed that the CME had a prominent electrocatalytic effect, high sensitivity and excellent stability for the determination of monoamine neurotransmitters. When being applied as the liquid chromatographic detector, the CME exhibited a good linear relationship between the current responses and the analyte concentrations. The linear ranges were over three orders of magnitude and the detection limit was 2.0 × 10^-10 mol/L for norepinephrine （NE）, 1. 0 × 10^-10 mol/L for dopamine （DA）, 3. 0 × 10^-10 mol/L for 3, 4- dihydroxyphenylacetic acid （DOPAC）, 4.0 × 10^-10 mol/L for 5-hydroxytryptamine（5-HT） and 7.0 × 10^-10 mol/L for 5-hydroxyindoleacetic acid （5-HIAA）. The application of this method coupled with microdialysis sampling for in vivo determination of monoamine neurotransmitters in rat striatum was satisfactory . The results demonstrated that GABA could substantially increase striatal concentration of monoamine neurotransmitters.