蛛网膜下隙局部应用GDNF对脊髓前角运动神经元的保护作用

Protective effect of glial cell line-derived neurotrophic factor injected into cavitas subarachnoidealis on spinal front corner motor neurons

目的研究周围神经损伤后经蛛网膜下隙置管局部应用外源性胶质细胞源性神经营养因子(glial cell line-derived neu-rotrophic factor,GDNF)对脊髓前角运动神经元的保护作用。方法成年SD大鼠随机分为2组:GDNF组(坐骨神经切断术后给予GDNF)和NS组(术后给予生理盐水)。切断两组大鼠左侧坐骨神经致相应脊髓前角运动神经元部分损伤,行蛛网膜下隙置管,实验组注入外源性GDNF(10μg/ml),对照组注入同等剂量的生理盐水,于2,4,8周行坐骨神经功能指数检测;取L4-6节段脊髓标本冰冻切片,行胆碱酯酶(ChE)和酸性磷酸酶(ACP)染色并进行图像分析。结果GDNF组脊髓前角运动神经元ChE阳性颗粒面积比NS组有明显提高(P<0.05),ACP阳性颗粒面积低于NS组(P<0.05);GDNF组坐骨神经功能指数亦优于NS组。结论周围神经损伤后通过蛛网膜下隙注入外源性GDNF对相应的脊髓运动神经元有保护作用。

Objective To investigate the effect of exogenous glial cell line-derived neurotrophic factor（GDNF） infused into the cavitas subarachnoidealis on spinal front corner motor neurons after sciatic nerve axotomy. Methods Forty-eight healthy SD rats were randomly divided into 2 groups：NS group and GDNF group.The left sciatic nerve in rats were cut off. And then 0.9% saline and GDNF solution were injected into cavitas subarachnoidealis at L4-6 in NS group and GDNF group,respectively.At first sciatic function index（SFI）was detected at weeks 2,4,8,respectively.The specimen of L4-6 spinal cord were taken and sectioned at different times.The cholinesterase（ChE）and acid phosphatase（ACP）in motor neurons were stained and analyzed by image analysis software for evaluating the condition of motor neurons. Results In GDNF group,ChE was significantly higher than in NS group,while ACP was lower than in NS group.SFI was higher in GDNF group than in NS group. Conclusion The exogenous GDNF infused into the cavitas subarachnoidealis could protect the degenerated spinal motor neuron from death after sciatic nerve injury.