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 (P<0.05, P<0.01). 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.
Keywords: Point GV 1 (Changqiang); acute spinal cord injury; brain derived neurotrophic factor (BDNF); electroacupuncture (EA); nerve growth factor (NGF).