Hypoxic Preconditioning Astrocytes Secrete GDNF To Reduce Neuronal Apoptosis

ObjectiveTo observe the influence of GDNF secreted by preconditioning astrocyteson the neurons.MethodsThe rats’ neurons and astrocytes were cultured by the method of enzymedigestion combined with mechanical separation. Cells were shown to beastrocytes and neurons by immunocytochemistry, which application of specificanti-GFAP, NSE antibody. To determine the LDH and find out thepreconditioning and hypoxia time. Astrocytes were separated to differentgroups, the level of GDNF in astrocytes media were detected by ELISA. Topreparate ACM1, ACM2and ACM3. neurons were divided into normal controlgroup, preconditioning and hypoxia group, hypoxia group, using different ACMto culture the neurons, to detecte the apoptosis of neurons byAnnexinV-FITC/PI FCM technique.ResultsNeurons can be used in the experiment at the6th, and astrocytes can beused in the experiment at the9th.60min OGD caused a significant increase onthe l lekage rate of LDH from cultures of neurons and astrocytes (p<0.05). Inthe hypoxia group, the expression of GDNF increased markedly at6h afterreperfusion, was peak at24h（p<0.05）. Expression of GDNF in preconditioningand hypoxia group was increased more significant than that in hypoxia group and preconditioning group. The FCM showed clearly that the rate of apoptosisin hypoxia group was higher than that in preconditioning and hypoxiagroup(p<0.05). The rate of apoptosis in ACM1and ACM3groups were higherthan that in ACM2group (p<0.05).Conclusionscould induce the expression of GDNF in astrocytes and could decrease theneuronal apoptosis.