中文摘要：

目的：观察神经生长导向因子Slit2在大鼠急性脊髓损伤后表达变化和分布情况，探讨轴索再生导向机制。方法：成年SD大鼠用Allen’s方法制作脊髓挫伤（SCI）模型，分别于挫伤后第2，4，7，14天取材，半定量RT—PCR分析Slit2 mRNA的表达变化，免疫荧光激光共聚焦扫描观察Slit2蛋白在脊髓损伤区的分布。结果：RT—PCR显示SCI后出现Slit2转录上调，表达量持续增高并于伤后第7天达到顶峰，之后逐步下降；免疫荧光则显示Slit2阳性颗粒先后出现在脊髓损伤区灰质胶质细胞中及神经元胞膜上，以前角、中央管及中线周围和后角较为聚集。结论：成年大鼠脊髓急性损伤后存在Slit2表达一过性上调并在损伤区灰质内广泛分布，可能对再生轴索的导向性生长发挥重要作用。

英文摘要：

Objective： To observe the Slit2 expression distribution and expression changes during spinal cord injury（SCI） of grown rats, and to investigate the molecular biological reason for the regenerative guidance of growth cone. Methods： The model of SCI was made with Allen＇s method. Seventy-two adult SD rats were randomly divided into SCI groups, sham operation group and normal control group. After the spinal cords of rat were injured, semi-quantitative reverse transcription polymerase chain reaction was applied to detect the expression changes of Slit2 mRNA; immunofluorescence was performed to detect the location of Slit2 protein expression in the gray matter. Results： The expression of Slit2 mRNA in damaged spinal cord appeared at the 2nd day post-trauma at a low level and increased significantly afterwards, which reached the peak at the 7th day post-trauma, then began to decrease during the following phase. The Slit2 immunofluorescence positive signal appeared at the extensive area of spinal cord gray, located in the astrocyte. Conclusion： This study demonstrates that Slit2 mRNA was expressed in the damaged local and vicinity part of gray matter, and it is likely to play a role in the axon regeneration after SCI.