Investigation Of Protection Effect Of Erythropoietin On Rat Cerebral Ischemia Damage

Objective:Erythropoietin is a cytokine of stimulating akaryocyte synthesis, recent research discover erythropoietin can preserve brain tissue and can decrease apoptosis. The experiment main approach protection effect of erythropoietin on rat cerebral ischemia damage and effect of HSP27,VEGF expression.Methods:1 A lot of healthy majority SD rats of masculinity(54) is divide into at random 3 group:sham operation group,ischemic-hypoxia group , ischemic-hypoxia group+EPO preconditioning group,each group is divided into 3 time point and is observed express of HSP27,VEGF in the different period,another is normal control. Decapitation and reciping brain is performed after 12h,24h,48h of ischemia-reperfusion, normal group is executed directly and brain tissue is obtained, it is formed paraffin section and undertake immunity staining of HSP27 and VEGF.2 Another healthy majority SD rats of masculinity is divide into at random 4 group: normal control, sham operation group,ischemic-hypoxia group, ischemic-hypoxia group+EPO preconditioning group,each is six. Learning and memory test in rats and TTC staining is commited after ischemia-reperfusion 24 hours.Results:1 HE staining:In ischemic-reperfusion group,we see that neuron is rarefaction , cell spaces is accreted and a great quantity nerve cell is degeneration and necrosis,it mainly display cell body shrinkage,karyopycnosis and chromatospherite vanishing; EPO group have more survival nerve cell and its degree of injury is obviously lessen;in sham operation group, nerve cell is normal and only observe of individual cell diminution ,nucleus anachromasis.2 Immunity staining Expression of HSP27 in brain tissue:endochylema and nucleus of nerve cell can see manipulus amber grains in normal group and sham operation group;buffy grains of endochylema and nucleus of nerve cell in ischemic-reperfusion group and EPO group is increased.The expression of masculine cell population in EPO group is junior to ischemic-reperfusion group in ischemic-reperfusion 12 hours,it has statistical significance between groups(P<0.01),;manipulus amber grains of endochylema and nucleus of nerve cell in EPO group increase significantly in ischemic-reperfusion group in 24 hours,in 48 hours, it has statistical significance between groups(P<0.01);in comparison with normal group and sham operation group, it has statistical significance(P<0.01) after ischemic-reperfusion group in 12 hours,in 24 hours,in 24 hours. It has not statistical significance between normal group and sham operation group(P>0.05).Expression of VEGF in brain tissue: cytoplasm of nerve cell can see manipulus amber grains in normal group and sham operation group, amber grains of cytoplasm of nerve cell obviously increase in ischemic-reperfusion group and EPO group. Amber grains of cytoplasm of nerve cell in EPO group increase significantly than in ischemic-reperfusion group in 12 hours,in 24 hours,in 48 hours, it has significant statistical significance between groups(P<0.01);in comparison with normal group and sham operation group, it has statistical significance ( P < 0 . 01) after ischemic-reperfusion group in 12 hours,in 24 hours,in 24 hours; It has not statistical significance between normal group and sham operation group(P>0.05).3 Infarct volume:After brain tissue section is colored by TTC,we can see albedo infarct focus,its infarct volume percentage is (22.38±4.34)% in ischemia- reperfusion group, (11.29±2.78)% in EPO group, in comparison with ischemia- reperfusion group,brain infarct volume of EPO group obviously diminish(P<0.01),sham operation group can not see brain infarct focus.4 The statistical analysis of test of learning and memory in rats:1)in comparison with normal group and sham operation group,essay frequency increase obviously in ischemic-reperfusion group(P<0.01); in comparison with ischemic-reperfusion group, essay frequency in EPO group decrease obviously, it has significant difference(P<0.01); It has not statistical significance between normal group and sham operation group(P>0.05).2) in comparison with normal group and sham operation group,test time obviously extend in ischemic-reperfusion group and its correct frequency degrade, it has statistical significance(P<0.01);in comparison with ischemic-reperfusion group, test times decrease and its correct frequency increase, it has significant difference(P<0.01); It has not statistical significance between normal group and sham operation group(P>0.05).Conclusion:1 EPO preconditioning group can protect ischemic-reperfusion injury,its protection is concerned with up-regulate HSP27,VEGF unit of ischemia side.2 In cerebral ischemic-reperfusion injury early stage, HSP27 promote apoptosis at first,then inhibit apoptosis.3 EPO preconditioning can promote restoration of learning and memory function of rat.