电针“长强”穴对大鼠急性脊髓损伤后神经生长因子和脑源性神经营养因子表达的影响

Effects of electroacupuncture at “Changqiang”(GV 1) on expression of nerve growth factor and brain derived neurotrophic factor in rats after acute spinal cord injury

目的:观察电针"长强"穴对急性脊髓损伤后神经生长因子(NGF)及脑源性神经营养因子(BDNF)表达的影响,探讨电针长强穴治疗急性脊髓损伤的作用机制。方法:将24只成年雌性SD大鼠随机分为电针组、模型组、假手术组,每组8只。假手术组只采用椎板摘除暴露脊髓但不予打击,模型组和电针组采用改良Allen’s法制备急性脊髓损伤模型。电针组在造模成功后采用电针"长强"穴治疗,每天治疗1次,连续治疗7 d;假手术组、模型组每天均抓取1次,不予其他任何干预。术后第1、3、5、7天对各组大鼠进行BBB(basso beattie bresnahan,BBB)评分直至取材,术后7 d取材,灌注固定、石蜡包埋。采用尼氏染色法观察脊髓及神经元形态变化,免疫荧光法检测脊髓中NGF和BDNF的表达情况。结果:术后第3、5、7天,电针组BBB评分均高于模型组(P<0.05,P<0.01)。尼氏染色显示,假手术组脊髓灰质呈蝴蝶状,结构完整,灰白质界限清楚;模型组脊髓灰质结构不完整,局部可见体积大、颜色较深的瘀血斑块等;与模型组比较,电针组瘀血面积较小,神经元水肿较轻,神经元形态较好,未见空泡样改变。免疫荧光检测,与假手术组比较,模型组和电针组NGF和BDNF表达均显著升高(均P<0.01);与模型组比较,电针组NGF、BDNF表达显著升高(均P<0.01)。结论:电针"长强"穴能促进大鼠急性脊髓损伤后NGF、BDNF的表达,提高模型大鼠BBB评分,有利于急性脊髓损伤的修复。

Objective To observe the effects of electroacupuncture（EA） at ＂Changqiang＂（GV 1） on expression of nerve growth factor（NGF） and brain derived neurotrophic factor（BDNF） in rats after acute spinal cord injury（ASCI）, and to explore the mechanism of EA at ＂Changqiang＂（GV 1） on ASCI. Methods Twenty-four adult female SD rats were randomly divided into an EA group, a model group and a sham operation group, 8 rats in each one. The rats in the sham operation group were treated with laminectomy to expose the spinal cord without any strike. The rats in the model group and EA group were treated with modified Allen＇s method to establish ASCI model. After model was established, the rats in the EA group were treated with EA at ＂Changqiang＂（GV 1）, once a day for continuous 7 days. The rats in the sham operation group and model group were treated with immobilization, once a day, without any other interventions. The basso beattie bresnahan（BBB） was evaluated 1, 3, 5, 7 days after operation. 7 days after operation, the rats were sacrificed with perfusion and the spinal cord was embedded with paraffin. The morphological changes of spinal cord and neuron were observed by Nissl＇s staining method; the expressions of NGF and BDNF were detected by immune fluorescence method. Results 3 days, 5 days and 7 days after operation, the BBB scores in the EA group were higher than those in the model group（P0.05, P0.01）. The Nissl＇s staining indicated the gray matter of spinal cord was butterfly-shaped with complete structure and clear boundaries between the gray and white matter; the tabby-shaped Nissl bodies were observed in cytoplasm. There were incomplete gray nucleus, big and saturate local stasis plaque. Compared with the model group, the smallerarea of blood stasis, less severity of neuron edema, better morphology of neuron and no vacuole change were observed in the EA group. The immune fluorescence results indicated the expressions of NGF and BDNF in the model group and EA group were higher than those in the sham operation group（all P〈0.01）;the expressions of NGF and BDNF in the EA group were higher than those in the model group（both P〈0.01）. Conclusion EA at ＂Changqiang＂（GV 1） could improve the expression of NGF and BDNF and increase the score of BBB in rats with ASCI, which is beneficial to the repair of ASCI.