神经生长导向因子Slit2在成年大鼠急性脊髓损伤后的表达

目的观察Slit2在大鼠急性脊髓损伤后不同时点表达量的变化和分布，探讨轴突再生导向机制。方法成年SD大鼠采用Allen’s法制作脊髓损伤（SCI）模型，分别于损伤后第2、4、7、14天取材，半定量逆转录-聚合酶链反应（RT-PCR）分析Sht2 mRNA表达水平变化，免疫组织化学法观察Slit蛋白在损伤脊髓区的分布情况。结果RT—PCR提示脊髓损伤后Slit2即开始出现转录上调，表达量持续增高并于第7天达到顶峰，之后逐步下降；免疫组织化学提示Slit2阳性信号先后出现在急性SCI区灰质胶质细胞及神经元胞质中，以前、后角及中央管周围较为聚集。结论大鼠SCI后有Slit2表达上调出现并在损伤脊髓灰质广泛分布，可能是轴索再生过程中生长锥导向性生长的关键调节者。

Expression of Slit2 in rats after aute spinal cord injury

Objective To observe the expression and distribution of Slit2 in rats after acute spinal cord injury (SCI) and the mechanism of of the growth cone guidance.Methods SCI model of adult SD rats was established by using Allen's method.The samples were taken on the post-injury day 2,4,7 and 14.By using semiquantative RR-PCR,the expression of Slit2 mRNA was detected.Immunocytochemistry was done to detect the distribution of Slit-2 protein expression.Results RT-PCR revealed that the ex- pression of Slit-2 mRNA in the injured spinal cord was up-regulated,reached the peak at 7th day,then gradually decreased.Immunocytochemistry indicated the positive signal of Slit 2 appeared at the extensive area of spinal cord gray,located in the astrocytes.Conclusion In rats after SCI,Slit 2 mRNA was up- regulated and extensively distributed in the injured spinal gray matter.Slit 2 is likely to do something im- portantly with axon regeneration after SCI.