三七总皂苷对脊髓损伤后BDNF的表达及运动功能的影响

Effect of tPNS on Spinal Cord Injury and the Influence on BDNF Expression

目的:探讨三七总皂苷(total panax notoginseng saponins,tPNS)对脊髓半横断损伤后对脑源性神经营养因子(Brain-derivedneurotrophic factor,BDNF)表达以及运动功能恢复的作用的影响。方法:大鼠随机分为正常组和实验组,实验组大鼠脊髓T10右侧半横断模型,损伤后15min,腹腔注射三七总皂苷,剂量为20mg.kg-1,以后每天给药一次,溶媒对照组注射等量生理盐水。术后进行BBB评分和斜板实验检测;动物分别存活1d、3d、7d、14d、28d后,采用免疫荧光化学方法检测脊髓损伤远侧端BDNF表达的变化。结果:BBB评分及斜板实验结果显示,三七总皂苷能明显促进脊髓损伤后运动功能的恢复,尤其是损伤后7d和14d,三七总皂苷组评分明显高于溶媒对照组。免疫组化结果显示:脊髓半横断损伤后,损伤远侧端损伤侧BDNF的表达强于对侧,损伤侧BDNF的表达呈现出1d,3d逐渐增强,7d达高峰的趋势,14dBDNF的表达逐渐下降,至28d仍略高于正常组。三七总皂苷组和溶媒对照组相比,BDNF表达的时间趋势相同,但相同时间点BDNF的表达强于对照组,尤其是3d、7d。结论:三七总皂苷能增强脊髓半横断损伤后BDNF的表达,这可能是其改善脊髓再生的微环境,促进脊髓损伤后运动功能恢复的机制之一。

Objective： To investigate the effect of tPNS on spinal cord injury and the influence on BDNF expression. Methods： The right side of the T 10 spinal cord was transected to establish the spinal cord injury model, tPNS was injected intraperitoneally at the dose of 20mg.kg-1 after spinal cord hemisection injury, once a day. The vehicle control group was administrated with equivalent saline. BBB score and IP score were assessed after spinal cord injury. BDNF expression changes in distal spinal cord were detected by immunohistochemistry at ld, 3d, 7d, 14d, 28d. Results： BBB score and IF score showed that compared with vehicle control group, TPNS can significantly promote the recovery of motor function, especially at 7d and 14d aider spinal cord injury. Immunohistochemistry showed that after T10 spinal cord hemisection injury, BDNF expression in the injured side of distal segment spinal cord were stronger than the contralateral side. In the ipsilateral gray matter, BDNF expression increased gradually at ld, 3d and peaked at 7d; BDNF expression gradually decreased at 14d, and still slightly higher than the normal group at 28d. BDNF expression in TPNS group was in the same trend with vehicle control group, but the expression of BDNF was higher than the control group at the same time point, in particular, at 3d and 7d. Conclusion： tPNS can enhance the expression of BDNF after spinal cord injury, which may be one of the mechanisms of its effect to improve the microenvironment of the spinal cord regeneration and then promote motor functional recovery.