天麻钩藤方对自由活动大鼠脑缺血海马细胞外液递质氨基酸的影响

目的 :观察天麻钩藤方 (天钩方 )对不完全脑缺血清醒自由活动大鼠海马细胞外液递质氨基酸的影响。方法 :用CMA微透析采样系统收集双侧颈总动脉结扎和放松引起的清醒自由活动大鼠不完全缺血前、缺血期间及再灌后大鼠海马细胞外透析液 ;用高效液相色谱 电化学法测定透析液中谷氨酸 (Glu)、牛磺酸 (Tau)、精氨酸(Arg)、γ-氨基丁酸 (GABA)和半胱氨酸 (Cys)的浓度。结果 :天钩方中剂量组可升高正常大鼠脑海马细胞外液GABA和Tau的浓度。与模型组比较 ,大鼠不完全缺血 120min时 ,天钩方中和大剂量组的Glu水平分别降低了 38.64%和31. 35% ,Tau升高了 13.99%和 12.86 % ,GABA升高了 25.89%和 33.99% ,Cys降低了 40.93%和 42.08% ,Arg升高了16.95%和 8.96% ;再灌 120min时 ,天钩方中和大剂量组的Glu的水平分别降低了 14.55%和 11.48% ,Tau升高了16.13%和 14.03% ,GABA升高了 24.41%和 2.622%。结论 :天钩方能增加正常大鼠海马细胞外液中抑制性氨基酸的浓度 ,抑制缺血再灌引起的兴奋性氨基酸的过度释放 ,增加Arg和抑制性氨基酸的浓度 ,从而发挥神经保护作用。

Effects of Tianma Gouteng Fang on transmitter amino acids in the hippocampus extracellular liquids in freely moving rats subjected to brain ischemia

Objective: To observe the effects of Tian ma Gouteng Fang (TGF) on the transmitter amino acids in the hippocampus extracellu lar liquids in freely moving rats subjected to incomplete brain ischemia. Method: Hippocampus extracellular liquids was collected conti nuously by the microdialysis sampling technology in freely moving rats during pr e-ischemia, incomplete ischemia and reperfusion periods induced by the occlusi on and loose of both common carotid arteries. Each dialysate sample was assayed for GABA, Tau, Glu, Cys and Arg with HPLC-electrochemical detector. Result: TGF increased the concentrations of GABA and Tau in the extracellular liquids of rat hippocampus. Compared with the model group, the concentration of Glu in the middle and large dosage groups of TGF, during the 1 20 min of ischemia, reduced by 38.64% and 31.35%, Tau increased by 13.99% a nd 12.86%, GABA advanced 25.89% and 33.99%, Cys decreased by 40.93% and 42 .08%, Arg raised to 116.95% and 108.96%, respectively. After 120 min of re perfusion, the concentration of Glu decreased by 14.55% and 11.48%, Tau incr eased by 16.13% and 14.03%, GABA increased by 24.41% and 26.22%, respectiv ely. Conclusion: TGF can increase the concentration of i nhibitory amino acids in hippocampus extracellular liquids of rats and inhibit t he excessive release of excitatory amino acids and raise the concentration of th e inhibitory amino acids and Arg during the ischemia-reperfusion periods. Ther efore, TGF can play the neuroprotective role.