中文摘要：

目的：研究不同剂量U0126对低频磁刺激促进星形胶质细胞迁移作用的影响,以选择合适的阻滞剂量。 方法：24只SD大鼠按U0126剂量被随机分为对照组（0mg/kgU0126,n=6）、低剂量组（0.1mg/kgU0126,n=6）、中剂量组（0.2mg/kgU0126,n=6）、高剂量组（0.4mg/kgU0126,n=6）,四组的刺激参数都为频率1Hz,强度1.52T,刺激量为30脉冲;均采用溴已锭注射入脊髓左侧背索复制局灶性的脊髓损伤模型。刺激后第14天,大鼠被处死,采用图像分析系统观察GFAP、MAP-2和ERK1/2的表达及脊髓损伤空洞体积的变化。 结果：随着U0126剂量的增加,在第14天时空洞的体积逐渐增大,GFAP、ERK1/2的阳性表达逐渐减弱,与对照组相比具有显著性差异（P〈0.05）,U0126中剂量组和高剂量组作用则无明显差异（P〉0.05）;病灶区域MAP-2均呈阴性表达。 结论：不同剂量的U0126可翻转磁刺激引起的星形胶质细胞的迁移,0.2mg/kg是较合适的剂量。

英文摘要：

Objective：To investigate the effects of U0126 of different doses on the ability of low frequency magnetic stimulation promoting astrocyte migration and to select suitable dose of U0126. Method：Twenty-four adult healthy SD rats were selected to receive injection of 0.5ml of 1% ethidium bromide （EB） in PBS into the dorsal spinal cord funiculus on the left side at T10-11 level to make located spinal cord injury models and randomly divided into four groups.The four groups were exposed to magnetic stimulation （1Hz, 1.52T,30pulses） at the following dose respectively： 0mg/kg U0126（control group）,0.1mg/kg U0126（low-dose group）, 0.2mg/kg U0126 （middle-dose group）,0.4mg/kg U0126 （high-dose group）. On the day 14 after stimulation, the rats were sacrificed and the expressions of glial fibrillary acidic protein（GFAP）, microtubule associated protein-2 （MAP2）, extracellular signal-regulated kinase1/2 （ERK1/2） and the volume of holes were detected with immunohistochemistry. Quantitative analysis of the expressions of GFAP,MAP-2 and ERK1/2 were performed with the image analysis system. Result：With the increase of U0126 dose,the volume of hole increased on day 14 （P〈0.05）. In the lesion area,the expressions of GFAP and ERK1/2 could be found,while MAP-2 could not. Significant differences were revealed in the expressions of GFAP、ERK1/2 among the four groups, it was significantly lower in U0126 groups than that in control group（P〈0.05）. while the middle-dose group had similar effect with the high-dose group（P〉0.05）. Conclusion：U0126 of different doses all could resupinate astrocyte migrations which were coused by low frequency magnetic stimulation, and 0.2mg/kg was the suitable dose.