Effect of acetaldehyde on neurotransmitter in the rat brain

采用体内微透析-高效液相色谱-电化学检测器相结合的方法，研究了高血乙醛(ACh)浓度对自由活动大鼠纹状体和伏核(NAC)中多巴胺(DA)、5-羟色胺(5-HT)和丹参素释放的影响。用顶空气相色谱法定量血液中ACh和Etoh的浓度。在脑内植入探头后，仅给予氰胺(CY，25，50和100 mg/kg，有效的乙醛脱氢酶抑制剂)+乙醇，CY+4-甲基吡唑(4-MP，82 mg/kg，有效的乙醇脱氢酶抑制剂)+乙醇，4-MP+乙醇，CY和4-MP。仅CY+EtoH组大鼠血中ACh浓度较高，纹状体和NAc中均可检测到丹参素。纹状体中DA、5-羟色胺和沙龙醇的释放量是NAC的两倍。各实验组纹状体和NAc的DA和5-羟色胺水平均无明显变化。在对照组(乙醇，1g/kg)中，纹状体和NAc内均未观察到丹参素的生成，也未观察到高浓度的ACh。结果表明：(A)高浓度乙醛可诱导脑内丹参素的生成，(B)脑内丹参素的生成可能依赖于DA和ACh的浓度，而高浓度的ACh和ACh对纹状体和NAc中DA和5-羟色胺的释放无明显影响。

Using in vivo microdialysis coupled with high performance liquid chromatography with an electrochemical detector, we investigated the effect of high blood acetaldehyde (AcH) concentration on the release of dopamine (DA), 5-hydroxytryptamine (5-HT) and salsolinol in the striatum and nucleus accumbens (NAc) of freely moving rats. AcH and EtOH concentrations in blood were quantified by head-space gas chromatographic method. After insertion of probe in the brain, rats were treated with cyanamide (CY, 25, 50 and 100mg/kg, a potent aldehyde dehydrogenase inhibitor) + EtOH, CY+4-methylpyrazole (4-MP, 82 mg/kg, a potent alcohol dehydrogenase inhibitor) + EtOH, 4-MP+EtOH, CY and 4-MP only intraperitoneally. High blood AcH concentration was observed only in the CY+EtOH groups, and in these groups, the salsolinol was detected both in the striatum and the NAc. The striatal release of DA, 5-HT and salsolinol was two-fold higher compared to the release in the NAc. The levels of DA and 5-HT did not change significantly in all experimental groups in either the striatum or the NAc. In the other groups including control (EtOH, lg/kg), no formation of salsolinol both in the striatum and the NAc, and no high AcH concentration was observed. With the increase in the doses of CY following EtOH, the peak concentration of salsolinon and blood AcH increased significantly.Our study indicate that (a) high acetaldehyde concentrations induce the formation of salsolinol in brain, (b) salsolinol formation in brain may can dependent on the concentration of DA and AcH, and cthere is no effect of high AcH and EtOH concentration on DA and 5-HT release both in the striatum and the NAc.