RESUMO
<p><b>OBJECTIVE</b>To study the effect of glutamate on the expression of vascular endothelial growth factor (VEGF) mRNA and protein in cultured rat astrocytes under hypoxia.</p><p><b>METHODS</b>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% 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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Glutamate 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.</p>
