The Infact Of SDF-1?/CXCR4 Expression Level Of Cocl₂ Preconditioning In Cerebral Infarction Rats

Objectives By TTC staining and HE staining observing the organization pathology change of Hypoxic ischemiaafterbrain, application immunohistochemical and Westanern blotting method detect the expression changes of SDF- 1?/ CXCR4 in rats cortex. To discuss the brain protective effect of Cocl2 pretreatment and the effect of the expression changes of SDF- 1 ? CXCR4, further to dissuss the effect of SDF- 1?/ CXCR4 in the brain protective effect of hypoxia preconditioning.Methods The 252 SD rats distinguish into Sham group(n=84), IR group(n=84),HPC group(n=84).By different of ischemia reperfusion time is divided into 6 subgroups,6 h?24 h?3 d?5 d?7 d and 14 d,every subgroup 14 rats. Modified Zea Longa method preparate the focal cerebral ischemia model, In each time point three groups for NSS to assessment rats neurological severity and then Put to death,to separate rats brain for brain tissue,by TTC staining evaluation the volume of cerebral infarction; HE staining observing the organization pathology change of Hypoxic ischemiaafterbrain; immunohistochemical method to observe the SDF-1?and CXCR4 expression changes of of three groups rats cortex in each time point, under microscope to count the number of SDF-1? and CXCR4 positive cells; Western-blotting method to observe the SDF-1?and CXCR4 expression changes of of three groups rats cortex in each time point. The observed value to EXCEL database after finishing using SPSS17.0 statistical software package for data analysis. The analyzed result was expressed as mean±SD( x ±s).Comparison between groups of the same point in time using the t test, comparison between different time points in the group using single factor analysis of variance.Results 1.Sham group does not appear pathological symptoms of the nervous system,NSS0 score.IR group and HPC group rats had a highe score 6 h after surgery, the most obvious when in 3 d, had the highest score, after the peak, 5 d rating fell, 14 d score decreased obviously;and HPC group 24h~3d NSS score was significantly lower than IR, the different is important(P<0.05).2. It is no infarcts in each time point of Sham group;There is Obvious infarcts of 6h in HPC group and IR group, the volume of cerebral infarction tends to be stable of 24 h, Compare the volume of cerebral infarction of 24h?3d?5d ? 7d ? 14 d in HPC group and IR group,there is no statistical significance(P >0.05);The evaluation the volume of cerebral infarction of each time point in HPC group were higher than in IR group(P <0.05)?3. Sham group basic normal brain tissue cell structure;IR group visible organization sparse clearly, nerve cells deformation,nuclear pyknosis ? karyorrhexis ? karyolysis, and lose the complete structure, glial cell proliferation? infiltration, edema obviously;HPC group ischemic zone surrounding the small, the number of nerve cells is more in the form of the infarction area, congestion and brain edema degree is lighter IR group.4. The SDF- 1? and CXCR4 expression increased significantly of 6h in HPC group, 7 d express achieve the highest level in each time point,then gradually reduce,there are still positive expression of 14 d. The SDF- 1?and CXCR4 positive cells expression of each time point in HPC group were higher than in IR group,the different is important(P <0.05).5. In the molecular weight of 11 ku and 43 ku detected SDF- 1? and CXCR4 positive stripe respectively.There is a small amount of alpha SDF- 1? and CXCR4 protein expression in Sham group rats cortex tissue; IR group and HPC group SDF- 1 and CXCR4 protein expression is significantly increased of 6h in rats cortex tissue,7d to the peak, there are still positive expression of 14 d; HPC group of SDF- 1? and CXCR4 protein expression were higher than in IR group at each time point,the difference was statistically significant(P <0.05);and IR group of 14 d SDF-1? protein expression was lower than that in group 7 d(P <0.01),but there was no significant difference between two time points in the HPC group(P >0.05).Conclusions 1.Cocl2 pretreatment could improve cerebral infarction rats nerve function score.2. Cocl2 pretreatment can reduce infarct volume, And increase the survival of nerve cells, improve cell activity, and improve cerebral edema.3. Cocl2 pretreatment can raise SDF- 1 and CXCR4 expression, may through this way induced cerebral ischemic tolerance,and give play to the role of brain protection, promote the recovery of neural function.