电针对局灶性脑缺血成年大鼠内源性神经干细胞增殖的影响

目的：研究成年大鼠脑缺血后缺血脑区神经干细胞增殖情况及电针干预对其影响,探讨电针治疗缺血性脑损伤的作用机制。方法：采用开颅热凝闭法制作大脑中动脉闭阻（MCAO）模型,随机分为模型组与电针组,缺血后用溴脱氧尿苷（BrdU）腹腔注射标记增殖的神经细胞。选用“大椎”、“百会”行电针干预,采用BrdU免疫组化观察脑缺血后第3d、7d、14d与21d四个不同时相BrdU阳性细胞数量的变化情况。结果：脑缺血后不同时相缺血侧皮质、齿状回、纹状体和SVZ均有BrdU阳性细胞,其中第7d的阳性细胞数量增加最为显著（P〈0．01）;而且电针组在不同时相的细胞数量均较同时相模型组有明显的增加（P〈0．05或P〈0．01）。结论：缺血可激发相关脑区神经干细胞的增殖。电针可起到促进作用,推论这种作用可能是电针治疗脑缺血的重要作用机制之一。

Effects of electro-acupunctuce on proliferation of endogenous neural stem cells after focal cerebral ischemia in adult rats

Objective:To investigate the effects of electro-acupuncture(EA) on the proliferation of neural stem cells (NSCs) and neurogenesis in the regions of ischemic brain injury of rats and to explore the mechanism of EA in treating ischemic brain injury. Method:The model of permanent focal ischemia was made by heat-coagulation of the right middle cerebral artery(MCA) after craniotomy, and the rats were randomized into model group and EA group. After middle cerebral artery occlusion (MCAO), proliferating brain cells were labeled with bromodeoxyuridine (BrdU) and EA was applied to "Dazhui" and "Baihui" in EA group. At the 3rd, 7th, 14th and 21st days after cerebral ischemia rats(n=5) were killed and the number of proliferating cell was observed by Immunohistochemistry for BrdU. Result: BrdU-positive cells were found in cortex, dentate gyrus (DG), striaturn and subventricular zone (SVZ) at different time after cerebral ischemia, at the 7th day remarkably increased(P<0.01). The number of BrdU-positive cells in EA group was more than that in model group at different time (P<0.05 or P<0.01). Conclusion: Ischemia can stimulate the proliferation of NSCs and the proliferation can be promoted by EA in interrelated regions after focal cerebral ischemia. It may be one of important mechanisms of EA in treating ischemic brain injury to enhance endogenous neurogenesis after ischemia.