胶质细胞谷氨酸转运体及其在脑缺血和脑缺血预适应中的变化

兴奋性氨基酸转运体(excitatory amino acid transporters,EAATs)是摄取细胞外液谷氨酸、保持细胞外谷氨酸低浓度的主要机制,已发现了五种EAATs,其中胶质细胞谷氨酸转运体在终止谷氨酸能神经传递、维持细胞外液谷氨酸浓度处于低水平方面发挥更重要作用。胶质细胞谷氨酸转运体的表达和功能受谷氨酸及其受体、垂体腺苷酸环化酶激活多肽、生长因子、内皮素、一氧化氮等许多因素的影响,其表达减少及功能降低与脑缺血损害的发生和发展密切相关,脑缺血预适应可通过调控其表达或改善其功能而诱导脑缺血耐受。

Glial glutamate transporters and its change in brain ischemia and cerebral ischemic preconditioning

Excitatory amino acid transporters （EAATs） are the primary mechanism for clearance of glutamate in the extracellular fluid. Five kinds of EAATs have been found. Although both neurons and glia contain EAATs, it is generally accepted that the uptake capacity of astrocytes is much higher than that of neurons. Both the expression and the function of glial glutamate transporters are regulated by many factors such as glutamate and its receptors, pituitary adenylate cyclase-activating polypeptide, growth factors, endothelins, nitric oxide, etc. The decreased expression and dysfunction of glial glutamate transporters are tightly correlated with neuronal damages induced by brain ischemia. Through regulating the expression and improving the function of EAATs, cerebral ischemic preconditioning can induce brain ischemic tolerance.