神经系统内高亲和谷氨酸摄取及其调节影响因素

The High Affinity Uptake of Glutamate in Nervous System and Its Regulation by Various Factors

神经系统内高亲和谷氨酸（Ｇｌｕ）摄取是Ｎａ＋依赖性的，由Ｇｌｕ能神经末梢及胶质细胞膜上的Ｇｌｕ转运蛋白介导。已克隆得到四种Ｇｌｕ转运蛋白，分别为ＧＬＡＳＴ１、ＧＬＵＴ１、ＥＡＡＣ１及ＥＡＡＴ４。它们的所在部位、分布及药理学性质都有自己的特点。花生四烯酸、一氧化氮、氧自由基、蛋白激酶、细胞因子及生长因子等多种因素能调节或影响高亲和Ｇｌｕ摄取。很显然这些因素的调节或影响效应具有一定生理及病理生理意义。

The high affinity uptake of glutamate in nervous system is sodium dependent and is mediated by glutamate transporter proteins located both in the nerve endings which release glutamate as a transmitter and in the plasma membrane of glial cells. Four subtypes (GLUT1,GLAST,EAAC1 and EAAT4) of glutamate transporters have been cloned. The localizations,distributions and pharmacological properties for each of these subtypes are unique from one another. The high affinity uptake of glutamate is regulated by various factors, such as arachidonic acid, nitric oxide, free oxygen radicals, protein kinases, cytokines and growth factors.The regulations are obviously meaningful from the standpoint of physiology and/or pathophysiology.