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Objective:By establishing a carotid stenosis model, to investigate focal cerebral ischemia-reperfusion injury in rabbits after carotid on the the expression and significance of vascular endothelial growth factor (VEGF) and serine/threonine protein kinase (AKt).Methods:70 New Zealand rabbits were randomly divided into the following groups:normal control group (group A, n=5), sham stenosis group (group B, n=5), stenosis group (group C, n=5); narrow+sham ischemia group (group D, n=5), ischemia-reperfusion group (group E, n =25), stenosis+ischemia-reperfusion group (group F, n=25),; Then, according to reperfusion time, group E and F were divided into 5 groups named reperfusion 3 hours,6 hours,24 hours,48 hours and 72 hours group respectively. Group C, D and F were dealed with "suture needle control" the establishment of bilateral common carotid artery with moderate stenosis, After carried on stenosis surgery, group B, and group C, D, F were eturned to normal feeding for 15 days. Group E and F was to be focal cerebral ischemia reperfusion by artery occlusion (middle cerebral artery occlusion MCAO) in the right middle cerebral. Vascular ultrasound was used to detect vascular stenosis.2% triphenyltetrazolium chloride (TTC) staining was applied to test the infarct size and pathology. TUNEL in situ hybridization observe cerebral ischemic apoptosis in the hippocampus, and calculate the number of positive cells, We used immunohistochemistry to detect the expression of VEGF and AKt in hippocampus of cerebral ischemic, calculate IA values. These data were compared between groups and correlation analysis.Results:1.TUNEL detection:group A, B, C and D showed apoptotic cells occasionally, compared with that groups, the number of apoptotic cells in group E, F increased (P<0.01). at 3 hours reperfusion, and peaked at 6 hours. While, apoptotic cells in goup F was less than group E at the corresponding time (P<0.01).2.Immunohistochemical results:B group of very small amount of VEGF expression, C, D group was higher than VEGF A, B group (P<0.01), CD group than in AB group AKt expression (P<0.05), EF group at different time points VEGF, AKt expression of IA values were significantly different (P<0.01), E, F IA values between groups was statistically significant (P<0.01).Conclusion:1. Moderate carotid stenosis may be to some extent reduce the rabbit brain after focal ischemia-reperfusion injury.2. AKt may be involved in ischemic neuronal signal transduction, and possibly by upregulating the expression of VEGF, and serve to strengthen the role of ischemic tolerance.
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