Studies On Shuxuetong-induced Neuroprotection And It's Effects On The Expression Of HSP70,P53 In Rats After Focal Cerebral Ischemia-reperfusion Injury

Objective:To observe the changes of infarction volume,neuron morphous,neuron apoptosis and dynamic expression of HSP70,P53 in rat brain after cerebral ischemia-reperfusion injury . And then to explore the protection mechanism of Shuxuetong .Methods:Ninty-six healthy male rats were fractionated randomly four groups: normal control group,sham operation group,ischemia group,treatment group. Ischemia group and treatment group were fractionated measuring volume group and immunohistochemistry group again. Immunohistochemistry group were fractionated six subsets at different reperfusion points that were six hours,twelve hours,twenty-four hours,forty-eight hours,seventy-two hours,ninty-six hours after cerebral ischemia two hours. Every subset was six rats. The treatment group rats were injected Shuxuetong by abdominal after making cerebral ischemia model successly. The ischemia group rats were injected identical doses of Sodium Chloride by abdominal at identical time point. The morphology changes were observed by microscope and the expression of HSP70 and P53 protein were investigated by using immunohistochemistry techniques respectively, and DNA fragmentation were analyzed by using TUNEL technique and TTC staining were used to observe infarction volume which the focal cerebral ischemia was induced by the transient right MCAO in Sprague-Dawley rats .The behavior scales of neural function of cerebral ischemia-reperfusion injury (CI/RI) of the rats was used to evaluate the neural function .Results: TTC staining showed the infarction volume in Shuxuetong treatment group was much smaller than the pure ischemia-reperfusion injured group (P<0.01).The neural function of the rats in Shuxuetong treatment group was much better than pure ischemia-reperfusion injured group at all the time points except 6h point . TUNEL-positive cells were more apparent in the perifocal tissue and particularly in the inner border regions immediately adjacent to the ischemic core. We found apoptosis cells in ischemia group and Shuxuetong theatment group since 6h after MCAO, and reached their peaks at the time of 48h/72h after reperfusion respectively. The expression peak had been delayed at the Shuxuetong theatment group and the amount of apoptosis cells were decreased remarkably(P<0.05). There were slight immunity-positive cells of HSP70 in cerebral cortex and basal ganglia about 6h after ischemia-reperfusion. The ischemia group and treatment group reached peak at 24h time point together, but in treatment groups HSP70 positive staining cells were more than ischemia group at different time points after reperfusion .The expression of P53 protein appearanced at 6h after ischemia-reperfusion, it reached peak at 48h time point on the ischemia group , and it reached peak at 72h time point on the treatment group and the amount of immunity-positive cells of P53 were less obviously than the ischemia group(P<0.05).Conclusions:It proved that Shuxuetong could significantly reduce the cerebral ischemia-reperfusion injury. It could decrease the infarction volume and improve rat's neural function. The neuroprotction mechanism against cerebral ischemia-reperfusion injury maybe up-regulate the expression HSP70 and down-regulate P53, and then to inhibit apoptosis.