神经病理性疼痛大鼠脊髓背角中核转录因子-κB蛋白表达的变化

Expression of nuclear factor kappa B and neuropathic pain

目的观察大鼠脊髓背角中核转录因子-κB（NF-κB）在慢性坐骨神经挤压性损伤（CCI）疼痛模型中表达的变化规律。方法雄性SD大鼠48只，分为手术组和假手术组，每组24只，于CCI前1天、CCI后第1，4，7，14，21天各时间点测定机械痛阈及热痛阈后立即处死大鼠，每个时间点4只，取腰髓，采用Western blot方法测定NF-κB的蛋白表达变化。结果手术组大鼠术侧机械痛阈及热痛阈明显降低，脊髓背角中NF-κB水平表达增加，明显高于对侧和假手术组；NF-κB蛋白水平于CCI后第1天开始增加，第7天达到高峰（P〈0．01），于CCI后第21天仍维持于较高水平（P〈0．05）。结论CCI致大鼠脊髓背角NF-κB活化，参与神经病理性疼痛的调控过程。

Objective To investigate the expression of nuclear factor kappa B （NF-κB）in the lumbar spinal cord in chronic constrictive injury （CCI） of the sciatic nerve. Methods Forty-eight male Sprague-Dawley rats were divided into 2 groups （n = 24 in each）. The operation group received CCI of the sciatic nerve and the sham-operation group received a sham operation as a control. Their mechanical and thermal nociceptive thresholds were assessed with paw withdrawal latency （PWL） using von Frey filaments and radiant heating. Four rats were sacrificed at each time point and segments of their lumbar spinal cords were examined using Western blotting. Results Mechanical and thermal stimulation thresholds were reduced significantly after the operation. Expression of NF-κB protein increased significantly in the ipsilateral dorsal horn of the spine compared with the contralatcral side and compared with the sham-operation group. NF-κB protein expression began to increase on the 1 st day after the operation, reached a peak at the 7th day, and stayed high throughout the experiment. Conclusion NF-κB in the dorsal horn of the spine may be involved in neuropathic pain after CCI.