电针对局灶性脑缺血再灌注大鼠大脑皮层微血管超微结构及血管内皮生长因子表达的影响

目的:探讨电针对局灶性脑缺血再灌注大鼠大脑皮层的保护作用。方法:SD大鼠随机分为正常组(n=8)、假手术组(n=8)、模型组(n=32)、电针组(n=32),后两组再各分为再灌注后1d、2d、4d、8d4个亚组,每组8只大鼠。采用线栓法制备大鼠大脑中动脉闭塞模型。电针组于脑缺血0.5h再灌注1h后每天行1次电针治疗,取"百会"水沟"足三里"穴。透射电子显微镜下观察各组大鼠右侧大脑皮层微血管内皮的超微结构,逆转录酶-聚合酶链反应法检测各组大鼠右侧大脑皮层血管内皮生长因子(VEGF)mRNA的表达。结果:模型组大鼠的大脑皮层微血管超微结构损害明显,缺血侧大脑皮层VEGF mRNA表达与正常组、假手术组比较明显升高(P<0.05,P<0.01);电针组大脑皮层微血管超微结构明显改善,大脑皮层VEGF mRNA表达水平与相应时相的模型组相比均明显增强(P<0.01)。结论:脑缺血再灌注促使缺血脑区微血管内皮细胞VEGF mRNA合成;电针对脑缺血再灌注大鼠大脑皮层微血管的超微结构形态学损伤具有明显的保护作用,电针治疗可进一步促进缺血脑区微血管内皮细胞VEGF mRNA的表达并调控血管新生,帮助脑内微血管的功能重建是针刺发挥脑保护作用的途径之一。

Effects of Electroacupuncture on Microvascular Ultrastructure and VEGF Expression of the Right Cerebral Cortex in Focal Cerebral Ischemia/Reperfusion Injury Rats

Objective To study the protective effects of electroacupuncture(EA) on the cortical microvasculature in rats with focal cerebral ischemia/reperfusion injury(CI/RI).Methods Eighty SD rats were randomly divided into:normal group(n=8),sham-operation(sham) group(n=8),model group(n=32) and EA group(n=32).The CI/RI model was established by occlusion of the middle cerebral artery for 30 min and reperfusion for 1 day(d),2 d,4 d and 8 d respectively.EA was applied to "Baihui"(GV 20),"Shuigou"(GV 26) and bilateral "Zusanli"(ST 36) areas for 30 min,once daily for 1 d,2 d,4 d and 8 d.The right cortical microvascular ultrastructure was examined with transmission electron microscopy and cerebral vascular endothelial growth factor(VEGF) mRNA expression was detected by quantitative real-time PCR.Results The microvascular ultrastructure of the right cerebral cortex was severely injured in rats of the model group whereas greatly improved in rats of EA group.VEGF mRNA expression of the right cerebral cortex was increased significantly in the model group(P<0.05,P<0.01) and further upregulated in the EA group(P<0.01).Conclusion EA intervention can alleviate the injury of microvascular ultrastructure of focal ischemic cerebral tissue and upregulate cerebral VEGF mRNA expression,suggesting a role of EA in protecting the ischemic brain tissues by facilitating the angiogenesis of capillary vessels and the function reconstruction of the damaged microvasculature.