EGb761增强c-jun表达减少轴突撕脱后运动神经元的死亡

目的:观察EGb761对脊神经根撕脱后前角运动神经元c-jun表达和存活的影响。方法:成年Sprague-Dawley雌性大鼠180只,行脊髓C5-T1节段神经根撕脱术后,每日给予腹腔注射1mLEGb761(25mg·kg^-1),对照组注射同容积的生理盐水。治疗后4h、12h、1d、3d、5d、1周、2周、4周和6周9个时点分别处死动物,取C7脊髓节段行c-jun免疫细胞化学和中性红染色。定量比较两组c-jun阳性和存活的运动神经元数目。结果:对照组损伤侧运动神经元4h开始表达c-jun,1d达高峰,以后逐渐下降至术后2周。术后2周运动神经元开始死亡,4周-6周达高峰。EGb761组各时点c-jun阳性和存活的运动神经元数目都多于对照组。结论:EGb761能有效地减少神经根撕脱后运动神经元的死亡,机制可能与c-jun基因的上调有关。

Ginkgo biloba extract enhances c-jun expression and attenuates motoneuron death induced by root avulsion

AIM: To investigate the influence of Ginkgo biloba extract (EGb761) on c-jun expressions and motoneurons survival following root avulsion. METHODS: One hundred and eighty adult Sprague-Dawley female rats were randomly divided into control and EGb761 groups. Immediately after avulsion of C5-T1 nerve roots, the rats were injected ip with either 1 mL of EGb761 25 mg·kg^-1·d^-1 or the same volume of normal saline, and the treatment repeated everyday. At 4 h to 6 weeks following avulsion, the C7 spinal segments of all rats were collected and prepared for c-jun immunocytochemistry and neutral red stain. The numbers of c-jun positive and survival motoneurons were counted and compared between two groups at each time point. RESULTS: In control rats following avulsion, c-jun positive motoneurons appeared at 4 h, reached its maximum at 1 d and declined to 2 weeks. Avulsion-induced motoneurons death started at 2 weeks, climbed to its maximum at 4 weeks-6 weeks. In EGb761 treated rats, both numbers of c-jun positive and survival motoneurons were more than that in control group at each time point. CONCLUSION: EGb761 attenuates avulsion-induced motoneurons death, and this effect may be related to up-regulation of c-jun gene in avulsed motoneurons.