SD大鼠脊髓损伤后微环境中髓鞘相关抑制因子的表达

The Expression of Myelin Related Inhibitory Factor in Microenvironment after Spinal Cord Injury in SD Rats

目的观察SD大鼠在不同致伤势能的Allen’s模型和脊髓全切模型微环境中不同时间点的髓鞘相关抑制因子表达。方法选择125只成年雌性SD大鼠随机分为5组,每组25只, A组(假手术组), B组[20 g×5 cm,即致伤势能100 gcf (gram-cm force)], C组(20 g×10 cm,致伤势能200 gcf), D组(20 g×15 cm,致伤势能300 gcf)和E组(脊髓全切组)。采用Western blotting印迹分析法,在制模成功后1 d、5 d、7 d、14 d、28 d观察大鼠脊髓损伤(SCI)组织中勿动蛋白-A(Nogo-A)、髓鞘相关糖蛋白(MAG)、少突胶质细胞髓鞘糖蛋白(OMgp)等髓鞘相关抑制因子表达。结果整个实验中大鼠死亡24只(16.67%); B、C、D、E组SCI后1 d可见Nogo-A、MAG、OMgp表达,Nogo-A与MAG表达于SCI后7 d达峰值,28 d恢复到假手术组水平; SCI后1 d可见髓鞘中OMgp表达,5 d达峰值,28 d恢复至假手术组水平。结论 Nogo-A、MAG、OMgp在SCI后普遍呈现高表达,并在SCI后5～7 d达到峰值。

Objective To observe the expression of myelin related inhibitory factor in SpragueDawley （SD） rats at different time points in different injury potential energy of Allen’s model and spinal cord total cut model with the microenvironment. Methods One hundred and twenty five adult female healthy SD rats were selected and randomly divided into 5 groups with 25 in each, group A （sham operation group）, group B [（20 g × 5 cm, injury potential energy 100 gram-cm force （gfc））], group C （20 g × 10 cm, injury potential energy 200 gcf）, group D （20 g × 15 cm, injury potential energy 300 gcf）; group E（total spinal cord resection group）.The expression of myelin related inhibitory factors of neurite outgrowth inhibitor-A（Nogo-A）, the myelin associated glycoprotein（MAG）, and the oligodendrocyte myelin glycoprotein （OMgp） were analyzed by Western blotting after spinal cord injury （SCI） at 1 d, 5 d, 7 d, 14 d and 28 d after successful modeling. Results Twenty-four cases（16.67%） of SD rats were died in the whole experiment. The expression of Nogo-A, MAG and OMgp was observed at the first day after SCI in group B, C, D and E. The expression of Nogo-A and MAG reached the peak at the 7th day and returned to the levels of sham operation group on the 28th day. The expression of OMgp in myelin was observed at the first day after SCI, and reached the peak at day 5, and returned to the levels of sham operation group on the 28th day. Conclusion The Nogo-A, MAG and OMgp are highly expressed after SCI and those indexes are reached the peak 5～7 days after SCI.