| Background With the develop and aging of our society,the incidence rate,mortality rate and disability rate of ischemic cerebrovascular disease is becoming more and more higher than before. AS a result, it is necessary to explore the mechanism of Ischemic cerebrovascular disease. Studies shows that methods to restore blood supply in ischemic areas so that survive the dying neurons and glia cells and vascular endothelial cells is the key in the treatment of ischemic cerebrovascular disease. More attentions has paid on angiogenesis in cerebral ischemia by the means of vascular repair and regeneration inclinic therapic.Compared with VEGF-A,studies aimd at PLGF has been little focused,which is in the same family with VEGF-A. The role of PLGF was initially found to be with the angiogenesis of placental villus and maintain the growth and development of placenta.PLGF. Nowadays,much more connections have been revealed between PLGF and angiogenesis in the condition of myocardial ischemia,tumor,inflammation and wound healing and so on.This study aims to observe the variation of PLGF and its receptor Flt-1 in ischemic region of cerebral cortex in rat cerebral ischemia/reperfusion modle and under the intervention of electroacupuncture. And to explore the function of PLGF /F lt-1 in cerebral ischemia/reperfusion and the mechanism of electroacupuncture in improvin -g cerebral ischemic and angiogenesis in the brain.Objective (1)To investigate the effect of electroacupuncture on the expression of PLGF and Flt-1 of SD rat after focal cerebral ischemia/reperfusion.(2)To investigate the effect of PLGF and Flt-1 on revascularization after focal cerebral ischemia/reperfusion.(3)To investigate the mechanism of electroacupuncture in revasculari -zation for focal cerebral ischemia/reperfusion.Method Male SD (Sprague-Dawley)rats were randomly divided into control group(NC group), model group(I/R group) and electroacupunc -ture group (I/RE group). The model of focal cerebral ischemia /reperfusion was established by modified filament occlusion. According to accept reperfusion 1d,3d, 7d after 2h ischemia,I/R group and I/RE group were divided into 3 subgroups separately and EA was given at bilateral"Hegu"point(LI 4)in I/RE group.The immunohistochemical method was performed to detect the expression of PLGF and Flt-1 and western blot was used to detect the expression of PLGF in the cerebral context of ischemic area. The pathology differences of brain tissue were determined by HE staining . The differences of infraction volume after focal cerebral ischemia/reperfusion were determined by TTC staining. The neurological function impairment of focal cerebral ischemia/reperfusion was evaluated by neurological symptom score. The expression of PLGF and Flt-1 mRNA was detected by reverse transcription-polymerase chain reaction(RT-PCR).Result (1)neurological function deficit had been found in all groups. Neurological symptom scores diminished with the prolonged reperfusion time by the time points 1d,3d,7d in both I/R group and I/RE group. Compared with I/R group,I/RE group had a lower neurological symptom scores,but significant difference only existed in 7d group(P<0.05).(2)There are white fraction areas in both I/R group and I/RE group,but the fraction vessel in I/RE group was significant smaller than I/R group(P<0.05).(3)Immunohistochemical shows that PLGF-positive cells stained with yellow in cytoplasm mainly expressed in glia cells and vascular endothelial cells and neuron located in cortex and hippocampus. There are only a few PLGF-positive cells expressed in NC group while higher expression was found in all three time points both in I/R group and I/RE group compared with NC group. The expression of PLGF-positive cells was significant higher in 1d(P<0.01),and reach peak level at 3d(p<0.01). In each time point,the expression of PLGF -positive cells in I/RE group were significant higher than I/R group(P<0.01).(4)mmunohistochemical showed that Flt-1-positive cells stained with yellow in cytoplasm mainly expressed in cerebral cortex, hippocampus, vascular endothelial cells surrounding periventricular tissue and neurons . There was a very small amount of Flt-1-positive cellsexpressed in NC group. The expression of Flt-1-positive cells was significant higher in 1d(P<0.01) and reached peak level at 3d(p<0.01)and a little lower in 7d(P<0.01)in group.The expression variation in I/RE group was similar with I/R group,but significantdifferences only seen in 3d and 7d (P<0.01) not in 1d subgroup(P>0.05).(5)The expression of PLGF mRNA NC group has a small amount of PLGF mRNA expression. In I/R group, the expression of PLGF mRNA was higher in all three time points than NC group(P<0.01)and reached its peak level at 3d. Expression in I/RE group were significant higher than I/R group according 1d(P<0.05),3d(P<0.01), 7d(P<0.01),peak level also at 3d.(6)The expression of Flt-1 mRNA In I/R group, the expression of Flt-1 mRNA was higher in all three time points than NC group(P<0.01)and reached its peak level at 3d. Expression in I/RE group were significant higher than I/R group according 1d,3d, 7d (P<0.01).(7)Western blot to detect the expression of PLGF protein The expression of PLGF in NC group was low than other two group. In I/R group,the expression was significant increased at 1d(P<0.01)reached peak level at 3d(P<0.01).No significant difference was found at 7d (P>0.05).in I/RE group,there were significant higher expression of PLGF compared with NC group at every time point(P<0.01). The peak expression also found at 3d. I/RE group had significant higher expression than I/R group at 3d(P<0.01),7d(P<0.01),but not at 1d(P>0.05).Conclusion(1)EA at"Hegu"point can effectively promote the neurological function and decrease infraction volume by promoting revascularization in ischemic cortex after focal cerebral ischemia/reperfusion at SD rat.(2)EA at"Hegu"point can effectively promote revascularization by increaseing the expression of PLGF, Flt-1 mRNA and protein in ischemic cortex after focal cerebral ischemia/reperfusion at SD rat.(3)PLGF/Flt-1 axis have a important role of revascularization in ischemic cortex after focal cerebral ischemia/reperfusion at SD rat.
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