脊髓损伤后运动神经末梢中TrkA和NGF表达的研究

Expression of Tyrosine Kinase A and Nerve Growth Factor in Muscle of Adult Rats Following Acute Spinal Cord Injury

[目的]探讨脊髓损伤(spinalcordinjury,SCI)对下肢肌肉组织中高亲和性神经生长因子受体(transfectionofhighaffinitynervegrowthfactorygene,TrkA)和神经生长因子(nervegrowthfactor,NGF)表达的影响以及内源性神经营养素(neurotrophlns,NTs)的生物学作用模式。[方法]雄性成年SD大鼠15只随机分成正常对照组、假手术对照组和脊髓损伤组,麻醉后采用改良的Allen氏重物打击方法(50g／cm)损伤T12节段,应用免疫组织化学方法,观察正常、假手术和脊髓T12节段损伤48h后大鼠下肢肌肉组织中TrkA和NGF表达的情况。[结果]大鼠脊髓T12段损伤48h后,下肢肌肉中神经-肌肉接头处有TrkA明显表达,在肌细胞质中有较强NGF表达。正常和假手术组成年大鼠下肢肌肉中末见表达。[结论]脊髓损伤后神经生长因子和受体大量表达有利于受伤运动神经末梢摄取内源性神经营养素并上行转运至受伤神经元发挥其生物效应以促进损伤脊髓的修复。

[Objective] To study the expression of tyrosine kinase A (TrkA) in muscle of adult rats following spinal cord injury, and to explore action mechanisms of endogenous nerve growth factor(NCF).[Methods] Thee focal spinal cord injury was induced by compression,the expression of TrkA and NCF was studied by immunohistochemical method. [Results] Immunohistochemical study showed that TrkA was remarkably expressed at 48 hour after focal spinal cord injury in point of contact in nerve ending and muscle, and NCF was remarkably expressed at 48 hour after focal spinal cord injury in muscle cells.[Conclusion] The presence of TrkA in point of contact in nerve ending and muscle which may act as target tissue of NT-3 and NCF.The presence of TrkA benefit that neurotrophic factors were transported carriage to nerve tissue injured.