| ObjectiveThe high rate of disability of cerebrovascular diseasehas been a great obstacle to the quality of human' s life and socio-economic development. Focal ischemic cerebrovascular disease, as a main type of cerebral vascular disease, hasgreat significance in deeply studying of pathophysiologicalmechanisms and finding new treatment methods. Due to blocked blood vesse, regional cerebral blood flow decreased, eventually it lead to tissue hypoxia and cell death. At this point, body need to maintain oxygen' s balance and steady-state, in order to resist such negative factors. An importantmechanism is induce neovascularization, improve collatera1 circulation and increase cerebral blood flow, but this was limited.The studys of angiogenesis's molecular mechanisms show that the formation of new vascular is of great complication and is affected by many factors. Among those factors, so far, vascular endothelial growth factor(VEGF) is of most powerful. It can mediate angiogenesis after early cerebral ischemia by activating it's specific receptors. VEGF can beseen expression in early stage of cerebral ischemia, it isconsidered as a key factor to promote proliferation of endothelial cells which is the start link of neovascularization.VEGF can alsochange the permeability of the blood-brain barrier, promote the damage of vascular matrix, provide necessary micro-environment for angiogenesis. In addition, VEGFis important neurotrophic factor and protective factor, andinhibit neuronal apoptosis. The activation of VEGF dependson the regulation of Hypoxia Inducible Factor-1α(HIF-1α),and the activation of HIF-1αis considered the key to startthe hypoxic response, and HIF-1αcan regulate VEGF and its receptor (flt -1). My subject, used the middle cerebral artery occlusion models, observe the effects of electro-acupuncture on the expressions Of VEGFmRNA,HIF-1αmRNA and brainangiogenesis, explore the possible mechanism of effects of Electro-acupuncture on cerebral ischemia-reperfusion injury.Meterials and Methods120 SD rats were randomly divided into the normal control group, sham operation group,model group,electro-acupuncture treatment group. According to isehemia 30 min reperfusion 6h,12h,1d,2d,4d, both model group and electro-acupuncture treatment group were randomly divided into 5 subgroupsonce again. Normal control group and sham operationgroup have 10 in each group, model group and electro-acupuncture treatment group have 10 in each sub-group. Used the s uture, in MCA to establish MCAO isehemia-reprfusing model. The remarks of nerve function deficit referring to Zea-Longa' s 5 grades remarking standards, only rats with more thanone grade neurological dysfunction can be retained. The acupoints of "BAIHUI", "SHUIGOU" and "ZUSANLI" were selectedand density wave were used for electro-acupuncture treatment. Use immunohistochemical method to observe right side ofthe cerebral cortex of rats in each group' s changes of microvascular density ;use fluorescence in situ hybridizationto detect the expressions of VEGFmRNA and HIF-1αmRNA in right side of the cerebral cortex of rats in each group' s ,and analysize the effects of electro-acupuncture on the changes of different expressions of each factors concerning different points in time after Cerebral ischemia-reperfusion.ResultsThere is no significant difference in CD34 postive microvessel density among normal control group,sham operationgroup,both electro-acupuncture treatment group and model group' s sub-group of CIR 6h (P＞0. 05); while CIR12h,1d,2d,4d, right side of the cerebral cortex of rats in both electro-acupuncture treatment group and model group can be seen Obviously microvascular hyperplasia, there is significant difference compared to normal control group,sham operation group (P＜0.05).This indicates that after cerebral ischemia reperfusion ,tissues of ischemic areas exist Angiogenesis. Microvessel density in electro-acupuncture treatmentgroup' s sub-group of CIR12h,1d,2d,4d are higher than the corresponding phase of model group, this shows that elect ro-acupuncture could promote the process of angiogenesis after cerebral ischemia-reperfusion.The expressions of HIF-1αmRNA in rats brain of normalgroup and sham operation group are too weakly to see. In the ischemic cerebral cortex in rats of groups of electro-acupuncture treatment and model, the expressions of HIF-1αmRNA increased. There is no significant difference after CIR4d(P＞0.05) of these two groups; while the expressions of HIF-1αmRNA in electro-acupuncture treatment group' s subgroups of CIR6h,12h,1d,2d are higher than the correspondingphase of model group and there are significant differencesbetween the two groups (P＜0.05), This indicate that electro-acupuncture could promote the expressions of HIF-1αmRNAin ischemia cerebral cortex in the early stage of cerebralischemia-reperfusion.There is no significant difference in the expressions of VEGFmRNA in right side of the cerebral cortex of rats among normal control group,sham operation group,both electro-acupuncture treatment group and model group' s sub-groupof CIR 6h (P＞0.05); while CIR12h,1d,2d,4d, the expression goed up ,display significant difference compared to normal control group and sham operation group (P＜0.05),and the expressions of VEGFmRNA in electro-acupuncture treatment group's are higher than the corresponding phase of modelgroup, there are significant differences between the two groups (P＜0.05) and indicate that electro-acupuncture could promote the expressions of VEGFmRNA after cerebral ischemiareperfusionin cerebral cortex. ConclusionsAfter Cerebral ischemia-reperfusion, body start the process of angiogenesis, VEGF and HIF-1αparticipate in the process. Electro-acupuncture treatment can help to regulate theprocess of angiogenesis and promote the fomation of new vasculars in cerebral cortex after Cerebral ischemia-reperfusion injury, its mechanism may be relative to the promotion of expressions of HIF-1αand VEGF. |
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