Effect of hypoxic preconditioning on penumbra angiogenesis in mice with acute cerebral infarction

Objective To explore the effect of hypoxic preconditioning on angiogenesis in the cerebral ischemic penumbra.Methods Blb/c mice were randomly divided into four groups:normal group(N),sham operation group(C),acute cerebral infarction group(CI)and hypoxic preconditioning and cerebral infarction group(HP+CI).Immunofluorescence and laser confocal techniques were used to examine the fluorescence intensity change of VEGF and CD31 in the brain ischemic penumbra at 24h and 72h respectively after the model was successfully made.Results In group N and C,a small amount of VEGF and CD31 was expressed in the brain cortex,and in the experimental group(group CI and HP+CI),VEGF was expressed mainly in neurons in area of brain ischemic penumbra at 24h,while at 72h mainly in vascular endothelial cells in the area of ischemic penumbra.CD31 was expressed all in vascular endothelial cells in the ischemic penumbra area at 24h and72h.The expression of VEGF and CD3 in ischemic penumbra in experimental group(group CI and HP+CI)was significantly higher than that in group N and C(P0.01).The expression of VEGF and CD31 in ischemic penumbra in group HP+CI at 24h and 72h was significantly higher than that in group CI(P0.01).The expression of VEGF was positively related to that of CD31 according to Pearson's correlation analysis.Conclusion Hypoxic preconditioning may promote the formation of angiogenesis through increasing the expression of VEGF and CD31 in the brain ischemic penumbra in rats with acute cerebral infarction.