雷公藤多甙对异体神经移植后免疫反应及骨骼肌萎缩的影响

Effects of Tripterygium Glycoside on Immune Response and Skeletal Muscle Atrophy after Nerve Allograft

目的探讨雷公藤多甙对异体神经移植后免疫反应和骨骼肌萎缩的影响。方法用Wistar大鼠坐骨神经桥接SD大鼠10mm坐骨神经缺损。60只成年雄性SD大鼠(体重200～250g)随机分为4组(n=15):A、B组为新鲜异体移植,C、D组为供者神经雷公藤多甙预处理后移植。术后第2天予A、C组生理盐水,B、D组分别予雷公藤多甙5mg/(kg.d)和2.5mg/(kg.d),时间5周。术后定期观察移植神经和患侧骨骼肌大体及组织学变化,并分析肌纤维直径,透射电镜观察骨骼肌超微结构,免疫组化检测移植神经MHC-Ⅰ、Ⅱ分子表达和CD4+、CD8+T细胞入侵。结果移植神经炎症细胞浸润和骨骼肌萎缩,B、C、D组均明显轻于A组;骨骼肌湿重和肌纤维直径,A组明显低于B、C、D组(P<0.05),C组低于B、D组(均P<0.05),而B、D组间差异无统计学意义(P>0.05)。术后6周,A组肌小节结构消失,肌丝溶解严重和残存"Z"线片段,余组肌原纤维均排列整齐,明带、暗带和肌小节结构清晰。MHC-Ⅰ、Ⅱ表达和CD4+、CD8+T细胞入侵在术后第1周出现高峰;同一时相,B、C、D组显著低于A组(均P<0.01),B、D组低于C组(均P<0.05),而B、D组间差异无统计学意义(P>0.05)。结论雷公藤多甙能减轻失神经支配骨骼肌萎缩;雷公藤多甙预处理能降低供者神经抗原性,减轻异体神经移植后排斥反应和受者免疫抑制剂用量。

Objective To investigate the effects of tripterygium glycoside （TG） on the immune response and the skeletal muscle atrophy after nerve allograft. Methods SD rat＇s sciatic nerve 10 mm gap was repaired by Wistar rat＇s sciatic nerve. The SD rats were divided randomly into 4 groups （n= 15 each） ： groups A and B received fresh allografts, and groups C and D received nerve allografts pretreated with TG. The rats were given medicine for 5 weeks from the second day of the transplantation., groups A and C were given physiological saline, group B TG 5 mg/（kg. d）, and group D TG 2.5 mg/（kg.d）. Gross and microscopic observations were performed after operation, and the diameter of skeletal muscles was analyzed. The skeletal muscles ultrastructures were observed under a transmission electron microscope, and the expression of MHC- Ⅰ, Ⅱ , and the infiltrated CD4^＋ , CD8^＋ T-cells of allografts were detected by immunohistochemical method. Results The number of infiltrated cells of allografts was significantly less, and skeletal muscle atrophy significantly milder in groups B, C and D than in group A. The wet weight and the muscle fiber diameter in group A were significantly lower than in groups B, C and D （P〈0.01 or P〈0.05）, lower in group C than in groups B and D （P〈0.05）, but there was no significant difference between groups B and D （P〉0.05）. At the 6th week after operation, there was serious silk dissolution and sarcomere damage and fragmentary Z lines in group A, but the myofibrils arranged tidily in other groups, and they were clear on the light band and the dark band and the sarcomere. The expression of MHC- Ⅰ , Ⅱ and infiltrated CD4^＋ , CD8^＋ T-cells reached the peak at the first week. At the same time, the expression of MHC- Ⅰ ,Ⅱ and infiltrated CD4^＋ , CD8^＋ T-cells in groups B, C and D were significantly lower than those in group A （P〈0. 01）, lower in groups B and D than in group C （P〈0. 05）, but there was no significant difference between groups B and C （P〉0.05）. Conclusion TG could decrease the skeletal muscle atrophy due to denervation after nerve allograft. TG pretreatment could decrease the antigenicity of donor＇s nerve, and reduce the rejection and the dosage of immu nosuppressant of recipient after allograft.