Effect Of Ischemic Preconditioning On Expression Of VEGF,GLUT-1 And BAI1 After Focal Cerebral Infaction In Rat

Background and objectivesBrain ischemic tolerance ( BIT ) is the phenomenon whereby a preconditioning ischemia of brief duration, inadequate to infarct the brain, protects it from subsequent severe ischemia. Currently, there are a lot about the molecular mechanisms of ischemic tolerance, but the explanation is far from ideal.How to improve cerebral ischemic tolerance, increased the ability of anti-ischemic and hypoxia to reduce the injury of nerve and vascular after cerebral ischemia has been the focus of the study Neurology. The present experiment was conducted to study VEGF, GLUT-1 and BAI1 expression after ischemic preconditioning on a permanent middle cerebral artery occlusion (PMCAO) and to explore the protective mechanisms of ischemic preconditioning from the morphological.Methods1. 69 healthy adult male adult SD rats were randomly divided into4 groups: experimental group, control group, sham-operated group and normal group.2. The PMCAO model was set up With middle cerebral artery suture method for ischemic preconditioning for 15 minutes after reperfusion 48h.3. After cerebral ischemia, neurological scores, brain water content and histological changes was observed in order to understand neurological injury.4. After PMCAO 24 hours, VEGF, GLUT-1 and BAI1 be detected by immunohistochemistry and enzyme labeled immunosorbent assay (ELISA) to discuss the protective mechanisms of ischemic preconditioning. Results1. Ischemic preconditioning can induces brain ischemic tolerance.2. brain water content and neurological scores in ischemic preconditioning group were significantly lower than the non-ischemic preconditioning group.3. The Hematoxylin Eosin staining show that the damage of brain in experimental group is lighter than control group and sham group.4. Immunohistochemistry Results: In experimental group, VEGF and GLUT-1 expression increased significantly, while BAI1 expression significantly decreased, mainly in the infarct border zone of neurons, glial cells, vascular endothelial, etc. There are great differences in pretreatment group with non-pretreated group; no difference in control group with ham group.5. ELISA Results: In experimental group, VEGF and GLUT-1 content level was significantly higher increased significantly, while BAI1 content level decreased. There are great differences in pretreatment group with non-pretreated group(P <0.01); no difference in control group with ham group(P> 0.05).Conclusion1. Ischemic preconditioning can induce ischemic tolerance , and reduce neurological damage after cerebral infarction.2. Ischemic preconditioning can induce the decreased BAI1 expression and the increased VEGF and GLUT-1 expression, which can promote microvessel density, nutrient the brain. After brain ischemic tolerance, there are closely related to the neuroprotective effect with the expression of VEGF, GLUT-1 and BAI3.3. Cerebral ischemic preconditioning induces brain ischemic tolerance, probably to protect the blood vessels, provide the energy necessary to stabilize the membrane potential, reduc neuronal and vascular endothelial damage.