电针预处理对脑缺血再灌注损伤大鼠谷氨酸和γ-氨基丁酸的影响

Effect of electro-acupuncture pretreatment on glutamate and γ-amino butyric acid in rats following middle cerebral artery occlusion

目的 探讨电针预处理对脑缺血再灌注大鼠纹状体处谷氨酸(Glu)和γ-氨基丁酸(GABA)浓度变化的影响,探讨电针预处理对脑缺血再灌注损伤的保护机制。方法 将SD大鼠随机分为假手术组、缺血组和电针预处理组。电针预处理:电针刺激大椎、百会两穴,30min/d,共5d。采用Longa线栓法制作大脑中动脉缺血(MCAO)模型,采用微透析技术收集大鼠缺血前、缺血期间(40、80、120min)和再灌注后(40、80、120、160、200、240min)的脑细胞外液,以测定Glu和GABA的浓度变化。大鼠再灌注24h后给予神经行为学评分,评分完毕后立即处死并取脑做TTC染色。结果 缺血组和电针预处理组细胞外液Glu和GABA浓度在缺血期间(40、80、120min)和再灌注后(40、120、160、200min)均增加(P<0.01);电针预处理组Glu水平在缺血40、80、120min和再灌注后120、160min低于缺血组(P<0.05或P<0.01)。缺血组和电针预处理组GABA浓度在缺血期间和再灌注期间均增加(P<0.01)。电针预处理组GABA浓度在缺血40、80、120min和再灌注后160、200min与缺血组相应时间点比较显著升高(P<0.05或P<0.01)。电针预处理组再灌注后24h行为学评分明显低于缺血组(P<0.01),脑梗死体积明显小于缺血组(P<0.01)。结论 电针预处理对缺血再灌注大鼠有脑保护作用,这种保护作用可能与下调缺血区纹状体细胞外液Glu浓度和上调GABA浓度有关。

Objective To study the effect of electro-acupuncture pretreatment on glutamate(Glu) and γ-amino butyric acid(GABA) in rats following middle cerebral artery occlusion and to investigate the neuroprotective mechanism of electro-acupuncture pretreatment to cerebral ischemia injury.Methods SD rats were randomly divided into 3 groups:sham group,ischemic group and pretreatment group.The rats in the electro-acupuncture pretreatment group received electro-acupuncture at Baihui acupoint and Dazhui acupoint for 30 min per day,5 days at the awake station.After electro-acupuncture pretreatment,middle artery was occluded for 120 min,followed by reperfusion.Dialysate was collected from the striatum in vivo before occlusion and 40,80,120 min after occlusion as well as 40,80,120,160,200,240 min after reperfusion.The changes of neurological deficit scores were evaluated 24 hours after reperfusion,while the infarct volumes of brains was then measured with TTC staining immediately after the neurological outcome evaluation.Results The level of Glu and GABA in the ischemic group and the electro-acupuncture group increased significantly 40,80,120 min after occlusion and 40,120,160,200 min after reperfusion(P<0.01);The level of Glu in the ischemic group and the electro-acupuncture group was significantly lower than that in the ischemic group 40,80,120 min after occlusion and 120,160 min after reperfusion(P<0.01).The level of GABA in the electro-acupuncture group was significantly higher During ischemia and reperfusion(P<0.05 or P<0.01).The level of GABA in the electro-acupuncture group was significantly higher than that in the ischemic group 40,80,120 min after occlusion and 160,200 min after reperfusion.The neurological deficit scores in the electro-acupuncture group were significantly lower than those in the ischemic group(P<0.01).Meanwhile,infarct volume changes at ischemia-reperfusion 24 hours between different groups also had a significant difference(P<0.01).Conclusions Electro-acupuncture pretreatment can in a certain degree inhibit the excessive release of Glu and up-regulate the expression of GABA in striatum in the process of subsequent ischemic-reperfusion brain injury,which may be one of the protection mechanisms for the early ischemic brain injury.