硬膜外应用虎纹镇痛肽-Ⅰ对大鼠外周神经挤压再生模型脊髓背角c-fos表达影响的研究

Study of Impact of Applying HWAP-I Epidural on Rat Scarve Nerve Cruch Model with Mechanic Withdrawal Threshold and c-fos Expression in the Superficial Dorsal Horn

目的通过观察硬膜外给予虎纹镇痛肽-Ⅰ对大鼠外周神经挤压模型机械痛阈与脊髓背角c-fos表达的影响,探讨虎纹镇痛肽-Ⅰ对再生神经神经性疼痛的影响。方法雄性Wistar大鼠60只随机均分成3组,A组为坐骨神经挤压模型组;B组为坐骨神经挤压模型+虎纹镇痛肽-Ⅰ治疗组;C组为假手术组。分别制成模型后,术后21d起检测机械刺激阈值及c-fos表达计数。结果A、B组各项指标与C组比较有显著差异;A组与B组比较c-fos表达阳性细胞计数及机械痛阈均有显著差异。结论虎纹镇痛肽-Ⅰ能有效减轻再生神经的神经性疼痛程度,促进神经的完善修复。

Objective To observe machinery pain threshold and spinal dorsal horn c-fos expression in sciatic nerve injury rat model to investigate the impact of applying HWAP-I epidural on regeneration nerve’s neuropathic pain.Methods 60 male wistar rats were randomly divided into foue groups： sciatic nerve injury （group A,n=20） sciatic nerve injury with treatment of HWAP-I group （group B,n=20） sham-operation （group C,n=20） and. Food and water were available adlibitum, and the rats were kept in a colony room with an ambient temperature of 22°C, and a 12-hour alternating light-dark cycle. The rats in A and B groups underwent a sciatic nerve crush. Under Fluothane anesthesia the right sciatic nerve was crushed with a smoothed-tipped forceps for 30 seconds, until translucent. Six hours after opration, in B group, HWAP-I 50μg/kg of epidural injection were used once a day, and last a week. The right sciatic nerve was exposed but not crushed under the standard anaesthetic regimen in C group. The wound was sutured in all animals.The peocess of regeneration of peripheral nerve and neuropathic pain were evaluated at 21 to 39 days following opration Mechanic withdrawal threshold and thermal withdrawal latensy were assessed by von-fray filaments 21,24,27,30,33,36,39 d after opration. Five rats of each group were given innoxious touch-stimulus for 2 hours before killed 21,27,33,39d after opration. The spinal cord was obtained after death. Immunohistochemistry was employed to investigate the expression of the c-fos.Results From 21 to 39 days, the threshold of A or B group was significantly different as compared to the C group animals. The expression of c-fos had no significant difference between 27th and 39th day in A group. The expression of c-fos had no significant difference between 27th and 39th day in B group.And there was a significant difference in c-fos expression between A and B groups.Conclusion Applying HWAP-I epidural significantly reduced neuropathic pain of nerve regeneration in sciatic nerve injury rat model.