两种天然抗氧化剂对臂丛根性撕脱后脊髓运动神经元保护作用的比较

The comparative study of protective effect of two kinds of natural antioxidants on spinal motoneurons following brachial roots avulsion

目的 比较植物抗氧化剂TA90 0 1和EGb761对臂丛根性撕脱后C7前角运动神经元c jun、nNOS表达和运动神经元存活的影响。 方法 成年Sprague Dawley雌性大鼠 180只 ,随机分为TA90 0 1组、EG761组和对照组。行右侧臂丛神经根性撕脱术后 ,三组大鼠每天分别给予腹腔注射 1ml0 5 %TA90 0 1、0 5 %EGb761和生理盐水。治疗后 4h、12h、1d、3d、5d、1周、2周、4周和 6周取材 ,行c jun免疫细胞化学、NADPH d组织化学和中性红复染。 结果 c jun和nNOS仅在损伤运动神经元出现 ,c jun表达开始于 4h ,1d达高峰 ,随后下降直至 2周。nNOS表达从 5d开始 ,2周达高峰 ,以后逐渐下降至 6周。运动神经元的死亡开始于 2周 ,以 4周～ 6周最明显。TA90 0 1和EGb761治疗后都能上调c jun ,下调nNOS表达 ,提高运动神经元存活。EGb761上调c jun表达的程度明显强于TA990 1;两者减少NOS表达和提高运动神经元存活的效果一致。 结论 TA990 1和EGb761都有保护受损运动神经元的功效 ,nNOS表达与运动神经元死亡的关系更密切。

Objective To compare the effect of natural antioxidants TA9001 and EGb761 on c-jun, NOS expression and survival of spinal motoneurons following brachial roots avulsion. Methods One hundred and eighty adult Sprague-Dawley female rats were randomly divided into TA9001, ECb761 and control groups. The right C 5～T 1 nerve roots were avulsed and then the introperitoneal injection of 1ml of 0.5% TA9001, 0.5% EGb761 or normal saline was given immediately and once daily to the rats, respectively. The rats were killed after survival for 4 h, 12 h 1 d,3 d,5 d,and 1 week, 2 weeks, 4 weeks and 6 weeks. The cryostat sections of C 7 segment were prepared and carried with c-jun immunocytochemistry, NADPH-d histochemistry and neutral red counter stain. Results The c-jun and nNOS gene expression was only appeared in injured motoneurons. c-jun was first appeared at 4 h, reached its maximum at 1 d, and grandually decreased till 2 weeks. NOS was first checked at 5 d, mostly at 2 weeks and decreased until 6 weeks. Avulsed motoneuron death started at 2 weeks, reached its peak at 4～6 weeks. Both TA9001 and EGb761 can cause c-jun up-regulation, nNOS down-regulation and more motoneuron survival as compared to control. Furthermore, EGb761 had more power to enhance c-jun expression than TA9901 at each time point. Conclusion It seems that nNOS is more important in motoneuron death mechanism than c-jun. Treatment of either TA9901 or EGb761 can protect the injured motoneurons following root avulsion.