OBJECTIVETo study the effect of glutamate on the expression of vascular endothelial growth factor (VEGF) mRNA and protein in cultured rat astrocytes under hypoxia.

METHODSCultured 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% CO(2)), and those in the other two groups under hypoxic condition (94% N(2), 5% CO(2) and 1% O(2)). 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.

RESULTSThe expressions of VEGF mRNA and protein underwent no significant changes in the control glutamate groups, but increased obviously in both hypoxia and hypoxia+glutamate 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+glutamate group than in hypoxia group.

CONCLUSIONGlutamate at 1 micromol/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.