鞘内注射补体调节蛋白衰变加速因子对大鼠神经病理性疼痛的影响

目的 观察鞘内注射补体调节蛋白衰变加速因子（decay accelerating factor,DAF）对大鼠神经病理性疼痛（neuropathic pain,NPP）的影响,探索其在NPP发病机制中的作用.方法 健康雄性SD大鼠,体质量200～250g,选取鞘内置管成功的大鼠30只,采用随机数字表法,将大鼠随机分为3组（n=10）,即假手术组、CCI组和DAF组.后2组采用慢性坐骨神经损伤法制作动物模型,假手术组分离大鼠坐骨神经干后逐层缝合.DAF组于术前1d开始鞘内注射DAF溶液20μL,1次/d,连续7d,假手术组和CCI组在相同时间点鞘内注射等容量生理盐水.于术前,术后1、3、7d,用热刺激和机械刺激法测定大鼠的痛阈值变化.术后7d处死大鼠,取L4～6段脊髓背角,用Western-Blot测定其DAF蛋白含量.结果 与假手术组相比,CCI组和DAF组大鼠术后1、3、7d热痛阈值和机械痛阈值降低（P＜0.05）;与CCI组相比,DAF组大鼠术后3、7d热痛阈值和机械痛阈值升高（P＜0.05）.Western-Blot 检测显示,CCI组大鼠脊髓背角DAF表达显著低于假手术组（P＜0.05）;与CCI组相比,DAF组大鼠脊髓背角DAF表达上调（P ＜0.05）.结论 鞘内注射DAF可抑制大鼠NPP的痛觉过敏,脊髓背角DAF的表达变化与NPP形成有关.

EFFECT OF INTRATHECAL DECAY ACCELERATING FACTOR ON NEUROPATHIC PAIN IN RATS

Objective To investigate the effect of intrathecal decay accelerating factor （DAF） on neuropathic pain in rats,and to seek the role of DAF in the mechanism of NPP.Methods Thirty male SD rats weighting 200-250g in which intrathecal （IT） catheter was successfully implanted without complication were randomly divided into three groups （n =10 each）：sham operation group,CCI group,DAF group.Neuropathic pain was produced by chronic constriction nerve injury in CCI group and DAF group.20μL DAF was injected IT once a day for seven consecutive days in DAF group,while the equal volume of normal saline was given in stead of DAF in sham operation group and CCI group.Mechanical pain threshold and thermal pain threshold were measured before （baseline） and at 1,3,7d after operation.Then,the rats were sacrificed and L4-5 lumbar spinal tissues were removed for determination of protein expression of DAF by Western-Blot.Results Compared with sham operation group,mechanical pain threshold and thermal pain threshold were significantly decreased and the protein expression of DAF down-regulated in CCI group （P ＜ 0.05）.Compared with CCI group,mechanical pain threshold and thermal pain threshold were significantly increased and the protein expression of DAF up-regulated in DAF group（P ＜ 0.05）.Conclusion Intrathecal DAF protein may attenuate hyperalgesia of rats,which indicates the relation between the change of DAF protein and neuropathic pain.