电针对脊髓损伤后神经生长抑制因子Sema3A表达的影响

Effects of electro-acupuncture on expression of nerve growth inhibiting factor Sema3A after spinal cord injury

目的：观察电针对脊髓损伤后神经生长抑制因子Sema3A表达的影响，探讨电针对脊髓损伤修复的可能作用机制。方法：将成年雌性SD大鼠分为正常对照组、模型组和电针组，模型和电针组各分7、14、28d3个时间点，建立成年大鼠第9～10胸椎段脊髓全横断损伤模型。电针组于术后当天进行电针治疗，3个组均分别于术后7、14、28d取材，用免疫组织化学ABC法和图像分析技术检测脊髓内Scma3A的表达。结果：术后7、14d时，与正常对照组相比，模型组脊髓损伤处邻近组织内Sema3A表达增强；与模型组相比，电针组脊髓损伤邻近组织内Sema3A表达显著增加；而28d时，电针组、模型组、对照组的Sema3A表达基本一致。结论：电针早期能促进脊髓损伤后Sema3A的表达，从而增强Sema3A对迷乱性出芽的抑制作用，有利于正确的轴突出芽，这可能是其促进脊髓损伤修复的可能机制之一。

Objective： To explore the effect of electro-acupuncture on the expression of nerve growth inhibiting factor Sema3A （Sema3A） in the injured tissues of the completely transected spinal cord, and its mechanism in the repair of spinal cord injury （SCI）. Methods： Forty five adult rats were divided into a normal control group, a model group and an electro-acu- puncture group （ EC group）. All rats underwent complete transection between segment T9 and T10 of the spinal cord. Elec- tro-acupuncture treatment started on the same day after operation in the EC group. The rats were sacrificed on 7 d, 14 d and 28 d after operation. The expression of Sema3A in the tissues of the injured spinal cord was determined by immunohisto- chemical staining. The immunopositive gray scale of the immunoreactivity was detected with computer image analysis tech- nique. Results： The expression of Sema3A in the injured spinal cord was apparently increased in the model group from 7 d to 14 d after operation, compared with the normal control group. The expression of Sema3A in the injured spinal cord was re- markably increased by electro-acupuncture treatment, compared with the model group. On the 28 d, the expression of se- ma3A in all 3 groups was similar, which was near to the normal level. Conclusion： Electro-acupuncture can significantly im- prove the expression of Sema3A, which is an inhibitor of axon regeneration after SCI. And this effect may be one of the mechanisms by which electro-acupuncture can promote functional recovery after SCI.