早期电针对局灶性脑缺血大鼠双侧皮质脑源性神经营养因子表达的影响

关键词：电针  脑缺血  脑源性神经营养因子  交叉迁移  早期康复

Keywords:electroacupuncture  cerebral ischemia  brain derived neurotrophic factor  cross education  early rehabilitation

摘要：

      摘要 目的：观察早期电针治疗对局灶性脑缺血大鼠双侧皮质脑源性神经营养因子（BDNF-mRNA）的时序性变化，探讨电针治疗偏瘫的交叉迁移效果的分子生物学机制。 方法：用线栓法建立局灶性脑缺血模型，将建模成功的54只SD大鼠随机分为健肢治疗组（UALTG）、患肢治疗组（ALTG）、对照组（CG），各组再随机分为1周、2周、3周组，造模成功24h后对治疗组浅麻醉行电针穴位治疗，每组各时间段结束24h内分离缺血皮质及对侧同部位皮质，采用RT-PCR法测定BDNF-mRNA表达量。 结果：①对缺血皮质BDNF-mRNA表达的影响：ALTG组BDNF-mRNA在第7天、第14天、第21天时表达量均有增加，与CG组相比有显著性增高（P<0.01）,而UALTG组在第7天和第21天时表达量均有增加，与CG组相比有显著性增高（P<0.01）；在第7天和第21天时UALTG组较ALTG组表达量更高（P<0.01）。②对缺血对侧皮质BDNF-mRNA表达的影响:ALTG组在第7天和第21天时BDNF-mRNA表达量高于CG组（P<0.01）；UALTG组在第14天时表达量高于CG组（P<0.01），且ALTG组表达量同时也高于UALTG组（P<0.01）；而UALTG组和ALTG组在第21天时的表达量均下降，低于CG组（P<0.01）。 结论：早期电针治疗MCAO局灶性脑缺血大鼠健侧肢体和患侧肢体都能有效促使双侧皮质BDNF-mRNA的表达上调，具有明显的交叉迁移效果，且健侧较患侧更大幅度提高缺血皮质BDNF-mRNA的表达，这种变化可能是大鼠功能恢复较好和病死率较低的分子机制之一。

Abstract:

      Abstract Objective: To examine the temporal effects of electroacupuncture(EA) on the changes of brain derived neurotrophic factor(BDNF)-mRNA in bilateral cerebral cortexes after local cerebral ischemia in rats in order to approach the mechanism of cross education of EA on hemiplegia. Method: Fifty-four SD rats with middle cerebral artery occlusion (MCAO) were established the local ischemic models and randomly divided into three groups: control group (CG, n=18), unaffected limb therapy group (UALTG, n=18), and affected limb therapy group (ALTG, n=18). EA groups received EA at 24h after the onset of MCAO model. Six rats in each group were sacrificed in a random order, at the 7th, 14th and 21st d after modeling. Ischemic cerebral and the contralateral cortex were dissected quickly. The specimens were frozen in liquid nitrogen before analyse for BDNF-mRNA expression by RT-PCR. Result: ①The up-regulation expression of BDNF-mRNA in the ischemic cortex of ALTG demonstrated significantly higher than that of CG at the 7th d，14th d，21st d(P<0.01)，The level of BDNF-mRNA in UALTG was higher than that of CG at the 7th d,21st d，meanwhile，which was higher than that of ALTG(P<0.01)；②There was also a quickly high expression of BDNF-mRNA in the contralateral cortex of ALTG at the 7th d and 14th d，which was higher than that of CG (P<0.01). The expression of BDNF-mRNA in UALTG become higher than that of CG at the 14th d (P<0.01),but lower than that of ALTG(P<0.01), the levels of both EA groups were significantly lower than that of CG at the 21st d(P<0.01). Conclusion: The up-regulation expression of BDNF-mRNA level in ischemic and contralateral cortex were observed after EA on both side limbs, which indicated the effectiveness of cross-education.From the 7th d to the 21st d,The expression of BDNF-mRNA consecutively kept high level in ischemic cortex in EA groups,higher expression of BDNF gene induced by EA intervention on the unaffected limb, which showed EA intervention on the unaffected limb at earlier time might promote nerve-regeneration better in ischemic cortex, facilitate the balance of both side cortexes.This plasticity may be one of the mechanisms that promote better recovery and lower mortality in rats with MCAO.