大剂量甲基强的松龙对大鼠急性损伤脊髓Nogo-A表达量影响的研究

目的：研究大剂量甲基强的松龙对急性脊髓损伤大鼠脊髓Nogo-A蛋白表达量的影响。方法：采用allen’s打击方法，将大鼠分为正常组、急性脊髓损伤组（对照组）和急性脊髓损伤＋大剂量MP组，损伤大鼠Tg-T10节段，分别于术后3、7、14d取受损节段大鼠脊髓，运用Western-blot方法测定各时相点Nogo-A表达量及其变化，并以HE染色和免疫组化染色对受损脊髓进行形态学观察。结果：Nogo-A蛋白在各组大鼠脊髓组织中均呈阳性表达，损伤后对照组与MP组各个时相点Nogo-A表达均显著高于正常组（P〈0.05），7d时最高，后逐渐下降，但14d的表达量仍高于正常组。其中大剂量MP组与对照组在各个时间点的表达量具有显著差异（P〈0．05），MP组在各个时间点的表达量显著低于对照组。结论：Nogo-A是SCI后脊髓神经纤维再生的主要抑制因子，大剂量MP对Nogo-A的表达具有明显的抑制作用。

The study on the expression of Nogo-A protein in acute spinal cord injury rats treating with high dose methylprednisolone

Objective:To study the expression of Nogo-A protein in acute spinal cord injury rats treating with high dose methylprednisolone. Methods: According to Allen's model, SD rats were divided into three groups: the normal, the acute spinal cord injury (control groups) and the acute spinal cord injury supplying with methylprednisolone treatment group. The segments of T8 to T10 were injured, and then injury spinal cord was taken out at 3,7,14 days after operation, respectively. The expression of Nogo-A protein was detected by Western blot in each phase time. After staining with HE and immunohistochemistry, the morphology of injured spinal cord was observed under the microscope. Results: Nogo-A protein expressed in the three groups. After the injury, the expression of Nogo-A protein at each time phases in both control and MP groups were significantly higher than that in normal group (P<0.05). During the 7th day after damage, the highest point of Nogo-A protein expression appeared in both control and MP groups, thereafter, decreased gradually. However, Nogo-A protein expression was higher than normal group at the 14th day (P<0.05). There was significant difference in groups MP with high dose and control (P<0.05).The expression of Nogo-A protein at each phase time in group MP was significant lower than that in control group. Conclusions: Nogo-A is a major suppressor factor of spinal cord neuron fiber regeneration after spinal cord injury, and high dose MP can inhibit the expression of Nogo-A protein obviously.