Effect Of Limb Remote Ischemic Post-conditioning On Cerebral Ischemia-reperfusion Injury And Expression Of VEGF And MMP-9

Objective: The present study was to explore the neuroprotective effect of limb remote ischemic post-conditioning(RIP) on middle cerebral artery occlusion(MCAO) and was to investigate expression of VEGF and MMP-9 after RIP.Methods: 98 healthy adult male SD rats were randomly divided into three groups: Sham group, Model group(Model: using middle cerebral artery occlusion model) and ischemia-reperfusion+limb remote ischemic post-conditioning group(I/R+RIP group: give double the femoral artery 3 cycles of ischemia and reperfusion in preparation before MCAO model, each cycle 10 minutes-10 minutes of ischemia and reperfusion as RIP inducing conditions). After ischemia and reperfusion, model group and I/R+RIP group were further divided into three time point subgroups: 12 h, 24 h, 72 h groups. We assessed the neuroprotective effects of limb remote ischemic post-conditioning using Bederson way of neurological deficit scores at 12 h, 24 h and 72 h time point. We also determine the percent of cerebral infact volume at each point in time by H&E staining and magnetic resonance imaging(MRI). VEGF and MMP-9 expression in ischemic penumbra was detected by immunohistochemistry staining.Results:(1) In 24-hour subgroup, rats neurological deficit in the I/R+RIP group was significantly decreased(P<0.05), compared with the Model group.(2) The percentage of infarct volume in I/R+RIP group was significantly lower than those in the Model group after ischemia at each time point(P<0.01).(3) Compared with the Model group,VEGF expression was significantly increased but MMP-9 expression were significantly decreased in I/R+RIP group(P<0.05), and the difference reached a peak in I/R+RIP group at 24 hours compared with 12 and 72 hours time point(P<0.05).Conclusion:(1) RIP induces the reduced neurological deficit scores at 24 h and the ecreased percent of infact volume from 12 h to 72 h after ischemia, thus alleviating cerebral ischemia reperfusion injury.(2) There were significantly lower expression of MMP-9 in ischemic penumbra in RIP group with higher expression of VEGF after MCAO, suggesting that decreased MMP-9 and increased VEGF expressions were tightly associated with the neuroprotective effect of RIP.(3)RIP in the treatment of ischemic stroke has good research value and prospects.