低频电刺激改善脑梗死大鼠神经功能障碍的机制研究

目的探讨低频电刺激(LFS)对脑梗死大鼠神经功能和梗死侧脑组织神经干细胞(NSC)增殖、血管再生的影响。方法制作大鼠永久性大脑中动脉梗死模型(MCAO)，随机分为假手术组、对照组和实验组，每组又分为7 d 和14 d 两个亚组，每个亚组12 只。术后2 d 开始进行LFS治疗。采用大鼠神经功能缺损评分(NSS)评估大鼠神经功能缺损程度，运用免疫荧光染色检测大鼠梗死侧大脑侧脑室的室管膜下层(SVZ)的5-溴尿嘧啶脱氧核糖核苷酸(BrdU)，应用酶联免疫吸附测定法(ELISA)检测大鼠梗死侧大脑的基质细胞衍生因子-1(SDF-1)、血管内皮生长因子(VEGF)含量。结果LFS治疗后14 d，实验组大鼠NSS评分明显低于对照组和假手术组(P<0.01)；LFS 治疗后各时间点实验组大鼠梗死侧大脑的SDF-1、BrdU 和VEGF 水平均较对照组有不同程度的上调(P<0.01)。结论LFS 能改善脑梗死大鼠功能障碍，其可能机制是通过激活SDF-1/CXCR4 轴，进而发挥促进NSC增殖和血管再生作用。

Effect of Low Frequency Stimulation on Neural Dysfunction in Rats with Cerebral Infarction

Objective To investigate the effects of low frequency stimulation (LFS) on proliferation and angiogenesis of neural stem cells (NSC) in cerebral infarction side in rats. Methods The rats with permanent middle cerebral artery occlusion (MCAO) were randomly divided into sham-operation group, control group and LFS group, each group was divided into 7 days and 14 days subgroups with 12 rats in each subgroup. LFS therapy was started 2 days after operation. The degree of nerve function defect was evaluated with Neurological SeverityScore (NSS), and the 5-bromodeoxy-dine (BrdU) positive cells in the subventricular zone (SVZ) of cerebral infarction side were detected with immunofluorescence. Stromal cell-derived factor 1(SDF-1) and vascular endothelial growth factor (VEGF) in infarction side were detected with enzyme-linked immunosorbent assay (ELISA). Results The NSS score was lower in the LFS group than in the control group and the sham-operation group 14 days after surgery (P<0.01). The number of BrdU positive cells, the content of SDF-1 and VEGF in the ischemic side were more in the LFS group than in the other groups (P<0.01) after treatment. Conclusion LFS can improve the neurological function in rats with acute cerebral infarction, which may associate with activating SDF-1/CXCR4 axis.