中文摘要：

目的观察谷氨酸在缺氧条件下对星形胶质细胞血管内皮生长因子（VEGF）表达的影响。方法原代培养SD大鼠星形胶质细胞,传代后分为4组：①对照组;②谷氨酸组（1μmol/L）;③缺氧组;④缺氧＋谷氨酸组。缺氧条件为：（94%N2,5%CO2和1%O2）,每组包括6个时相点：0、2、4、6、8、12h（以缺氧后开始计时）,②和④组加入1μmol/L的谷氨酸。在不同时间点提取细胞总RNA,用Real time FQ-PCR法检测VEGF mRNA表达变化;ELISA法检测培养上清液VEGF蛋白表达变化。结果对照组和谷氨酸组（1μmol/L）各实验时相点星形胶质细胞VEGF mRNA和蛋白表达无明显变化。而缺氧组和缺氧＋谷氨酸组VEGF mRNA和蛋白表达却随实验时相逐步增高,分别在6和8h达最高,之后渐下降。缺氧＋谷氨酸组VEGF mRNA和蛋白表达上调较单纯缺氧组更为显著。结论谷氨酸（1μmol/L）可在缺氧条件下增强星形胶质细胞VEGF mRNA和蛋白表达上调,这可能与缺氧状态下星形胶质细胞表面谷氨酸受体的表达变化有关。

英文摘要：

Objective To study the effect of glutamate on the expression of vascular endothelial growth factor （VEGF） mRNA and protein in cultured rat astrocytes under hypoxia. Methods Cultured rat astrocytes were randomly divided control group, glutamate group, hypoxia group and hypoxia＋glutamate group. The cells in the control and glutamate groups were cultured under nomoxic condition （95% air and 5% CO2）, and those in the other two groups under hypoxic condition （94% N2, 5% CO2 and 1% O2）. The total RNA was extracted from the cells at different time points of hypoxic exposure for real-time FQ-PCR and ELISA to detect the expression of VEGF mRNA and protein in cultured astrocytes, respectively. Results The expressions of VEGF mRNA and protein underwent no significant changes in the control glutamate groups, but increased obviously in both hypoxia and hypoxia＋glumatate groups at 2, 4, 6, 8 and 12 h of hypoxic exposure. At these time points, VEGF expressions at both the mRNA and protein levels were significantly higher in hypoxia＋glumatate group than in hipoxia group. Conclusion Glutamate at 1 μmol/L can further increase the expression of VEGF mRNA and protein in astrocytes exposed to hypoxia, which may result from the adaptive changes of glutamate receptors in hypoxic astrocytes.