Objective: To observe the effect of electroacupuncture (EA) of "Shuigou" (GV26) on the activities of sonic hedgehog(Shh) signaling molecules (Shh, Ptch, Smo，Gli and Gli2) in ischemic brain tissues in rats with cerebral ischemia (CI), so as to explore its mechanisms underlying improvement of CI.
Methods: Male Wistar rats were randomly divided into blank control group(n=10), sham operation group (n=90), model group(n=90) and EA group (n=90). The CI model was established by occlusion of the right middle cerebral artery (MCAO). According to the postoperative time points of MCAO, the later three groups were further divided into 1, 3, 6, 9, 12 and 24 h, and 3, 7 and 12 d subgroups, with 10 rats in each subgroup. EA (15 Hz, 2 mA) was applied to GV26 for 20 min. The 1 h to 24 h subgroups were treated immediately after modeling, the 3-12 d subgroups treated one time a day. The neurological severity score (NSS, 0 to 18 points) was used to evaluate the rats' neurological function, and TTC staining was employed to assess the cerebral ischemic volume (percentage of cerebral infarct volume, CIV). Western blot was employed to detect the expression of Shh, Ptch, Smo, Gli1 and Gli2 proteins in the ischemic cerebral tissue.
Results: Compared with the sham operation group, the NSS scores of the model group increased at all time points (P<0.01). The percentages of CIV of the model group from 3 h to 12 d were obviously higher than those of the sham operation group (P<0.01). The NSS scores at 3, 7 and 12 d and the percentages of CIV at 1, 3, 7 and 12 d after MCAO were significant lower in the EA group than in the model group (P<0.05). The protein expression levels of Shh from 12 h to 12 d (i.e. 12 h, 24 h, 3, 7 and 12 d), Ptch from 6 h to 12 d, Smo from 9 h to 12 d, Gli1 at 9 h, 12 h, and from 3 d to 12 d, Gli2 at 6, 9 and 12 h, and 3 d were significantly higher in the model group than in the sham operation group (P<0.05, P<0.01), while those of Shh at 3, 7 and 12 d, Ptch from 24 h to 7 d, Smo from 12 h to 7 d, Gli1 from 24 h to 7 d, Gli2 at 12 h, 3 and 7 d were significantly higher in the EA group than in the model group (P<0.05, P<0.01). No statistical significances were found between the sham operation and the blank control groups in all the indexes mentioned above (P>0.05).
Conclusion: EA of GV26 can improve neurological function and reduce infarct volume in MCAO rats, which may be related to its function in up-regulating the activities of Shh signaling pathway in the ischemic cerebral tissues.
目的：观察电针“水沟”穴对大脑中动脉栓塞(MCAO)大鼠神经功能及缺血脑组织中sonic hedgehog(Shh)信号通路表达的影响，探讨电针促进脑梗死后神经功能恢复的作用机制。方法：Wistar大鼠随机分为假手术组、模型组、电针组各90只，空白组10只。采用腔内线栓法阻滞右侧大脑中动脉制备MCAO大鼠模型。电针组以15 Hz、2 mA的连续波电针“水沟”穴20 min，每日1次。造模后1 h、3 h、6 h、9 h、12 h、24 h、3 d、7 d、12 d，采用神经功能缺损(NSS)评分及TTC染色法观察各组大鼠神经功能缺损程度及脑梗死体积百分比，Western blot法测定大脑缺血组织中Shh、Ptch、Smo、Gli1、Gli2蛋白的表达水平。结果：与假手术组比较，模型组各时相NSS评分均升高(P<0.01)；与模型组比较，电针组3~12 d时NSS评分降低(P<0.05)。与假手术组比较，模型组3 h～12 d脑梗死体积百分升高(P<0.01)；与模型组比较，电针组24 h～12 d脑梗死体积百分降低(P<0.05)。与假手术组比较，模型组Shh蛋白在12 h～12 d 时升高(P<0.01)，Ptch蛋白在6 h～12 d 时升高(P<0.05，P<0.01)，Smo蛋白在9 h～12 d 时升高(P<0.01)，Gli1蛋白在9、12 h及3~12 d时升高(P<0.05，P<0.01)，Gli2在6~12 h及3 d时升高(P<0.01)；与模型组比较，电针组Shh蛋白在3~12 d时升高(P<0.05，P<0.01)，Ptch蛋白在24 h～7 d时升高(P<0.05)，Smo蛋白在12 h～7 d时升高(P<0.05，P<0.01)，Gli1蛋白在24 h～7 d时升高(P<0.05，P<0.01)，Gli2蛋白在12 h、3 d、7 d时升高(P<0.05，P<0.01)。空白组与假手术组各指标比较均差异无统计学意义(P>0.05)。结论：电针“水沟”可能通过上调MCAO大鼠Shh信号通路蛋白的表达，从而促进脑梗死后神经功能的恢复。.
Keywords: Cerebral infarction; Electroacupuncture; Shuigou(GV26); Sonic hedgehog signaling pathway.