谷氨酸对急性脑缺血再灌注大鼠皮层乙酰胆碱活性影响的在体动态电化学研究

DYNAMIC EFFECT OF GLUTAMATE ON ACETYLCHOLINE ACTIVITY IN RAT CEREBRAL CORTEX DURING ACUTE CEREBRAL ISCHEMIA AND REPERFUSION IN VIVO BY ELECTROCHEMICAL METHOD

为了研究脑缺血时兴奋性氨基酸与胆碱能神经的关系，采用双侧颈总动脉夹闭（ＣＣＡＯ）的脑缺血动物模型，用乙酰胆碱离子选择性微电极（ＡＣｈ－ＩＳＭｓ）检测皮层ＡＣｈ释放量，观察脑缺血再灌注时谷氨酸对大鼠皮层ＡＣｈ释放量的影响。结果表明：１０－１ｍｏｌ／ＬＧｌｕ对ＡＣｈ－ＩＳＭｓ无干扰作用，在生理状态下不能显著地促进皮层ＡＣｈ的释放，但可使脑缺血３ｍｉｎ时皮层ＡＣｈ释放量较未加Ｇｌｕ组增加５８．１％（Ｐ＜０．０１），再灌注后皮层ＡＣｈ活性恢复减慢。结果提示：Ｇｌｕ协同ＡＣｈ释放的效应在脑缺血时明显放大，推测Ｇｌｕ和ＡＣｈ可能在缺血性脑损伤中有放大的协同作用。

To study the relationship between excitatory amino acid and cholinergic nerve during cerebral ischemia, this research used the animial model of cerebral ischemia and reperfusion induced by bilateral common carotid artery occlusion (CCAO), applied ACh ion selective microelectrodes (AChISMs) to measure ACh output, observed the effect of glutamate (Glu) on ACh output in rat cerebral cortex during cerebral ischemia and reperfusion. The results showed that there was not interference of low concentration Glu (10-1 mol/L) on AChISMs, Glu 10-1 mol/L cannot evoke ACh release in neocortex significantly in physiological condition, but can evoke ACh release in neocortex to increase 581% significantly (P<001) after cerebral ischemia 3 minutes, and can lower the restoration of ACh activity after reperfusion. It was concluded that the effect of Glu on potentiating ACh release was magnified during cerebral ischemia, glutamate could cooperate with ACh in ischemia brain injury.