蛛网膜下腔灌注胶质细胞源性神经营养因子对损伤脊髓再生及功能恢复的影响

目的：探讨胶质细胞源性神经营养因子（GDNF）对大鼠脊髓完全性横断后脊髓再生及功能恢复的影响。方法：采用大鼠胸段（T7-T8）脊髓完全横切损伤模型，将SD雌性大鼠随机分为正常组（n=6）、假手术组（n=6）、单纯横断组（n=10）、GDNF治疗组（n=10）。于大鼠脊髓损伤术后不同时间点进行行为学评估。24周时行生物素葡聚糖胺（BDA）顺行示踪处理，取材前行电生理检测。所取脊髓标本作神经中丝（NF-200）、生长相关肽-43（GAP-43）、胶质原纤维生长蛋白（GFAP）免疫组化检查，并应用图像分析系统进行定量分析。结果：行为学评分表明，3周后，GDNF组好于单纯横断组（P〈O．05），术后24周，GDNF组和单纯脊髓横断组中均未记录到SEP波形，BDA示踪也未见伤区及远段蓝染的神经纤维，但GDNF组空泡样变较单纯横断组轻。免疫组化图像分析GDNF组的NF-200和GAP-43染色结果与单纯横断组间无统计学差异（P〉0．05）：但GDNF组GFAP染色明显弱于单纯横断组（P〈0．05）。结论：GDNF能一定程度上改善脊髓损伤区及两端的神经细胞功能，但没有功能意义上的神经纤维再生。

Effect of glial cell line-derived neurotrophic factor on injuried spinal cord in rats

Objective:To study the effect of glial cell line-derived neurotrophic factor(GDNF) on the regeneration and neurological functional recovery of transected spinal cord.Method:Thirty-two adult SD female rats were randomly divided into normal control group(n=6),sham operation group(n=6),spinal cord transection group(n=10) and spinal cord transection combined with treatment of GDNF(n=10).Behavioral evaluation,SEP,BDA tracing,NF-200,GFAP,GAP-43 immunohistochemistry were performed to assess the status of neurological deficit at 6 months after operation.Result:Compared with that in transected spinal cord rats,there was an apparent increase of the mean score of behavior in GDNF treatment group three weeks later(P<0.05).No wave of SEP was recorded in GDNF group and transected spinal cord group.No nerver fiber stained with blue was found in BDA tracing of GDNF group and transected spinal cord group.There was no significant difference of NF-200 and GAP-43 expression between transected spinal cord group and GDNF group,whereas GFAP expression in transected spinal cord group was significantly higher than that in GDNF group(P<0.05).Conclusion:GDNF is valuable to some extent for the regeneration of nerve fibers,but no functional regeneration of nerve fiber is observed.