电刺激对大鼠缺血性脑卒中的保护作用

目的探讨皮层电刺激对大鼠永久性缺血性脑卒中的保护作用。方法雄性sD大鼠随机分成对照组和实验组。实验组根据刺激频率不同分成2Hz组，20Hz组，100Hz组，100／2Hz组。建立永久性梗塞模型。梗塞3h后，电极植入右侧大脑缺血区皮层进行刺激。分别在梗塞5h和24h进行行为学评分。在梗塞24h行2％氯化三苯基四氮唑溶液染色测量脑梗死比。于刺激结束1h后取脑组织Westernblot分析脑源性神经营养因子（BDNF）和血管内皮生长因子（VEGF）表达量的变化。结果2Hz电刺激组在梗死比的减少及行为学评分的改善方面最显著（均P〈0．05）。VEGF的表达量下降，而BDNF表达水平较其他各组无显著性差异。结论对于脑缺血溶栓未通患者，皮层电刺激对脑缺血可能有保护作用。

Protection of electrical stimulation on cerebral ischemic injury in rats

Objective To investigate the nettroprotection of electrical stimulation on permanent middle cerebral artery occlusion model （pMCAO）.Metllods Adult male rats were randomly divided into two groups： control group and experimental group. Then the experimental group was further divided into four sub-groups： 2 Hz group, 20 Hz group, 100 Hz group and 103/2 Hz group. Three hours after occlusion, electrodes were implanted into the ischemic area in right cortex of the rats. Stroke animals were conducted the behavioral test at 5 h and 24 h after pMCAO. The hemispheric infarct ratio was evaluated by staining with 2,3,5-triphenyltetrazolium chloride at 24 h after pMCAO. One hour after electrical stinnalation, the rats were euthanized under deep anesthesia using chloralic hydras and then Western-blot analysis was used to analyze the expressions of brain-derived neurotrophic factor （BDNF） and vascular endothelial growth factor （VEGF）. Results Compared with other experimental groups, the hemispheric infarct ratio was significantly decreased and the function recovery was improved significantly in 2 Hz stimulation group. Furthermore, the levels of VEGF were down-regulated and there was no significant change of BDNF levels among the experimental groups. Conclusion Cortical stimulation after pMCAO can decrease the hemispheric ratio and promote the functional recovery. Cortical electric stimulation may be a potent therapeutic tool for cerebral ischemia.