脊髓背角膜结合型补体调节蛋白表达在大鼠神经病理性痛形成中的作用

Role of membrane-bound complement regulatory protein expression in spinal cord dorsal horn in develop- ment of neuropathic pain in rats

目的评价脊髓背角膜结合型补体调节蛋白表达在大鼠神经病理性痛形成中的作用。方法健康雄性SD大鼠，体重200—250g。取48只鞘内置管成功的大鼠，采用随机数字表法，将其分为4组（n=12）：假手术组（S组）、神经病理性痛组（NP组）、生理盐水组（NS组）和米诺环索组（M组）。NP组、NS组和M组采用坐骨神经环形结扎法制备大鼠神经病理性痛模型，S组只分离坐骨神经后逐层缝合。M组于结扎坐骨神经前1d开始鞘内注射米诺环素50μg，Ns组鞘内注射等容量生理盐水，1次／d，连续7d。于结扎坐骨神经前1d（T0）、结扎后1d（T1）、3d（T2）和7d（T3）时测定大鼠机械痛阈和热痛阈。于L痛阈测定结束后断头处死大鼠，取L4，5脊髓背角组织，分别用Westernblot法和RT-PCR法检测CD46、CD55、CD59蛋白及其mRNA的表达水平。结果与S组比较，NP组、NS组和M组T1-3时机械痛阈和热痛阈降低，L时脊髓背角CD46、CD55、CD59蛋白及其mRNA表达下调（P〈0．05）；与NS组和NP组比较，M组T2，3时机械痛阈和热痛阈升高，T3脊髓背角CD46、CD55、CD59蛋白及其mRNA表达上调（P〈0．05）。结论脊髓背角膜结合补体调节蛋白表达下调，补体异常活化参与了大鼠神经病理性痛的形成。

Objective To evaluate the role of membrane-bound complement regulatory protein expression in spinal cord dorsal horn in the development of neuropathic pain （NP） in rats. Methods Forty-eight male Spra- gue-Dawley rats, weighing 200-250 g, in which intrathecal catheters were successfully implanted without complica- tions, were randomly divided into 4 groups （n = 12 each）： sham operation group （group S）, group NP, normal saline group （group NS） and minocycline group （group M）. NP was induced by chronic constrictive injury of the sciatic nerve in NP, NS and M groups. Minocycline 50 μg was injected intrathecally once a day for 7 consecutive days starting from 1 day before ligation of the sciatic nerve in M group, while the equal volume of normal saline was given in stead of minocycline in NS group. Mechanical pain threshold and thermal pain threshold were measured at 1 day before ligation of the sciatic nerve （baseline, To ） and 1, 3, 7 days after ligation of the sciatic nerve （T1-3 ）. Then the rats we, re sacrificed at T3 and the lumbar segment （ L4.5 ） of spinal cord was removed for determination of the expression of CIM6, CD55, CD59 protein and mRNA in the dorsal horn of spinal cord by Western-blot and RT-PCR,respectively. Results Compared with S group, mechanical pain threshold and thermal pain threshold were significantly decreased at T1-3 and the expression of CD46, CD55 and CD59 protein and RNA was down-regu- lated at T3 in NP, NS and M groups （ P 〈 0.05）. Compared with groups NS and NP, mechanical pain threshold and thermal pain threshold were significantly increased at T2.3 and the expression of CD46, CD55 and CD59 proteinand RNA was up-regulated at T3 in M group （ P 〈 0.05） brane-bound complement regulatory proteins in spinal cord are involved in the development of NP in rats. Conclusion The down-regulated expression of mem- dorsal horn and abnormal activation of the complement