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运动训练对脊髓损伤大鼠脊髓内BDNF及其受体TrkB表达的影响

贺晓玉   

  1. 广东省体育科学研究所
  • 收稿日期:2013-10-22 修回日期:2014-02-23 出版日期:2014-06-15 发布日期:2014-06-15
  • 通讯作者: 贺晓玉

Effects of exercise training on expressions of brain-derived neurotrophic factor and tyrosine kinase receptor B in spinal cord of rats with spinal cord injury

  • Received:2013-10-22 Revised:2014-02-23 Published:2014-06-15 Online:2014-06-15

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摘要： 目的 研究运动训练对脊髓损伤（SCI）大鼠脊髓内脑源性神经营养因子（BDNF）及其酪氨酸激酶受体B（TrkB）表达的影响，探讨运动训练促进脊髓损伤功能恢复的可能机制。方法 24只成年雌性SD大鼠随机分为假手术组、损伤对照组和运动训练组。采用通用型脊髓打击器建立大鼠T10脊髓损伤模型。损伤后7天起，对SCI大鼠进行4周运动训练，假手术组和损伤对照组不进行运动训练。损伤前及损伤后第1、2、3、4、5周采用BBB评分评定运动功能。运动训练结束后(即损伤后5周)取大鼠T12～L1节段脊髓，免疫组织化学检测脊髓内BDNF和TrkB表达及分布，Western blot检测脊髓内BDNF和TrkB蛋白含量。结果 运动训练组和损伤对照组BBB评分均较损伤后第1、2周明显提高，运动训练组较损伤对照组增加更为显著（P<0.05）。BDNF免疫反应阳性产物多分布于脊髓前角，脊髓后角及中央管周围也有出现；运动训练组BDNF阳性染色颗粒增多，平均光密度值较假手术组及损伤对照组均显著增加（P<0.05）。TrkB免疫反应阳性产物于脊髓前角、后角、中央管周围等处均出现较多分布；运动训练组TrkB阳性染色颗粒增多，平均光密度值较假手术组及损伤对照组均显著增加（P<0.05）。Western blot结果显示运动训练组大鼠脊髓内BDNF及TrkB的表达较假手术组、损伤对照组均明显增加(P＜0.05)。结论 运动训练能诱导脊髓损伤大鼠脊髓内BDNF及其受体TrkB表达，促进SCI大鼠运动功能恢复。

关键词: 运动训练, 脊髓损伤, 脑源性神经营养因子, 酪氨酸激酶受体B

Abstract: Objective To investigate the effect of exercise training on the expression of BDNF (brain-derived neurotrophic factor) and tyrosine kinase receptor B(TrkB) in spinal cord of spinal cord injury(SCI) rats. Methods Spinal cord injury models were produced by universal spinal cord impact system. Twenty-four female adult Sprague-Dawley rats were randomly divided into 3 groups, exercise group (SCI-induction and exercises group, n=8), control group (SCI-induction without exercises group, n=8) and sham-operation group (no operation, without SCI and exercises, n=8). Exercise training began from 7th day after injury and lasted for 4 weeks. The locomotor function was assessed by Basso-Beattic-Bresnahan(BBB) scale before injury and at the 1st, 2nd, 3rd, 4th and 5th week post injury. The expression of BDNF and TrkB protein in spinal cords were detected by method of immunohistochemistry and Western blot. Results BBB scores in exercise and control groups were higher than that at 1 week and 2 week post injury, and BBB scores in exercise group increased more significantly than that in control group (P<0.05). In immunohistochemistry test positive immunologic reaction to BDNF protein was mainly located in anterior horn of spinal cord, the expression level in exercise group was significantly higher than that in sham-operation group and control group (P<0.05). In immunohistochemistry test positive immunologic reaction to TrkB protein was located in anterior horn and dorsal horn and central canal of spinal cord, the expression level in exercise group was significantly higher than that in sham-operation group and control group (P<0.05). Expression of BDNF and TrkB in exercise group rats after exercise for 4 weeks were significantly increased, compared with control group (P <0.05). Conclusion Exercise training may effectively induce the expression of BDNF and TrkB in spinal cords and promote the recovery of locomotor function of SCI rats.

Key words: exercise training, spinal cord injury, brain-derived neurotrophic factor, tyrosine kinase receptor B