The Study Of CXCR7 Expression In Hippocampus Of Cerebral Ischemia/reperfusion Rats And The Effection Of NBP-injection

Objective:This study was on the basis of cerebral ischemia/reperfusion(I/R)model by SD rats Combining with pathology,molecular biology and drug intervention.Discussed the CXCR7 expression changes in cerebral ischemia/reperfusion rat'hippocampus cells,and the expression of NBP injection after the intervention.Preliminary discussion the CXCR7' role in the nerve protection and the protective effect of NBP-injection.Method:Prepare 104 healthy male SD rats which weight between 250g-320g,then randomly divided into four groups:normal group(n=20),Sham-operated group(n?20),cerebral ischemia/reperfusion(I/R)(n?32)and butylphthalide intervention group(n=32).Both of the later two groups were randomly divided into four subgroups(8 rats for each subgroup):6 hours group(6h),1 day group(1d),3 days group(3d)and 7 days group(7d).Select Longa method to create SD ischemia/reperfusion model,and evaluate the nervus function coloboma of rats with the Bedersonl 5-grades evaluation method.Then use HE staining to observe the pathology of hippocampi.Apply the method of immunohistochemistry to test the protein expression of CXCR7,and use reverse transcriptase polymerase chain reaction(RT-PCR)to examine the expression of mRNA of CXCR7 in hippocampi.Results:1.Pathological observation results:The hippocampal CA3 neurons of SD rats were clearly structured in normal group and sham group,and have clear boundaries with no interstitial edema or obvious infarction.However,cerebral ischemia/reperfusion group showed a neuronecrosis of hippocampus,in which the neuron number was significantly reduced,and the lesion deteriorated with time.The intervention group showed a less decline of neuron number with clearer structure and no obvious interstitial edema when compared to cerebral ischemia/reperfusion group,and the damage of rat brain tissue was significantly lighter.2.Immunohistochemical results:(1)In various sham group and normal group reperfusion time point,CXCR7 basically no expression,comparing the two groups has no statistical significance(P>0.05).CXCR7 in cerebral ischemia/reperfusion of 6h group increased slightly,reaches a peak in 1d group,and then decreased gradually,but the expression is still higher than the sham group and the normal group.Its expression mainly located in the CA3 region neurons,microglia and endothelial cells.I/R group compared with the sham group and normal group,the CXCR7 differences were statistically significant(P<0.01);(2)In the intervention group,CXCR7 expression basically the same with I/R group,but the number of positive cells was more than I/R group,and the difference was statistically significant(P<0.05).3.RT-PCR test results:In rat hippocampal CA3 region of the sham group and normal group,almost undetectable CXCR7.In cerebral ischemia/reperfusion group CXCR7 mRNA began to increase at the 6h,peaked at 1d,then gradually decreased,but still higher than normal in all subgroups sham group and the normal group,the difference was statistically significant(P<0.01).In Butylphthalide intervention group,CXCR7 mRNA expression is basically the same trend with the I/R group,but CXCR7 mRNA expression level was significantly higher than the I/R group(P<0.05).Conclusion:1.The expression of CXCR7 in hippocampus of cerebral ischemia/reperfusion rats is significantly increased.2.Butylphthalide can promote the expression of CXCR7,and may plays a role to protect hippocampal neurons of cerebral ischemia/reperfusion rats.