重组人促红细胞生成素与甲基泼尼松龙早期治疗大鼠脊髓挫伤的形态学研究

A Comparative Morphological Study on Early Stage Treatment of Rat Spinal Cord Contusion with Recombinant Human Erythropoietin and Methylprednisolone

目的:比较重组人促红细胞生成素(recombinant human erythropoietin,rHuEPO)与甲基泼尼松龙(methylprednisolone,MP)早期治疗大鼠脊髓挫伤的形态学变化。方法:采用BenchmarkTM颅脑损伤撞击器制备大鼠脊髓挫伤模型,损伤30 min后,rHuEPO组腹腔注射(ip)rHuEPO(5 000 UI·kg-1.BW),MP组尾静脉注射(iv)甲泼尼龙琥珀酸钠(30 mg·kg-1.BW)。采用Harris氏HE染色,Luxol固蓝染色,神经元核抗原(neuronalnuclei,NeuN)和胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)免疫组织化学染色,观察损伤脊髓组织。结果:损伤1,3 d后,MP组挫伤中心及前、后3,5 mm处灰质前角神经元存活数量、残存髓鞘面积及抑制星形胶质细胞数均高于rHuEPO组。损伤14,28 d后,rHuEPO组挫伤中心及邻近部位囊腔区域面积和星形胶质细胞抑制率高于MP组。同时,rHuEPO组挫伤中心及前、后3,5 mm处灰质前角神经元存活数量、残余髓鞘面积均显著高于MP组(P<0.05)。结论:30 mg·kg-1.BW MP早期治疗大鼠脊髓挫伤第一周能显著改善神经元存活、髓鞘脱失和星形胶质细胞增生。随着时间的延长,rHuEPO的长期疗效逐渐显著。

Objective：To comparatively study the morphological changes of the spinal cord in rats by treatment with recombinant human erythropoietin （rHuEPO） and methylprednisolone （MP） at an early stage after contusion injury. Methods：Spinal cord contusion model in rats was duplicated with a BenchmarkTM stereotaxic impactor. 30 min after the procedure, animals were administrated with 5000 UI·kg-1·BW rHuEPO （ip） or 30 mg·kg-1·BW MP （tail intravenous injection）. Morphological changes were examined by using the Harris HE staining and Luxol fast blue staining methods in combination with the immunohistochemical NeuN staining and GFAP staining. Results：1 and 3 days after the contusion procedure, the number of survived neurons, the residual myelination area and the＆nbsp;reduction of astrocytes in the bilateral anterior horn of gray matter in and 3, 5 mm around the the injury center were significantly higher in MP group than in rHuEPO group. However, 14 and 28 days after the contusion procedure, the cavity area of and surrounding the spinal cord injury site and the reduction of astrocytes were significantly larger in rHuEPO group than in MP group. In addition, the number of survival neurons and residual myelination area 3, 5 mm surrounding the injury site were significantly larger in rHuEPO group than in MP group （P〈0.05）. Conclusion：MP （30 mg·kg-1·BW） treatment at the early stage after contusion damage （the first week） significantly improves the neuronal survival, reduces loss of the myelin sheath and inhibits the proliferation of astrocytes in rats with spinal cord injury. However, at a later stage （2~4 weeks after the injury） the effect of rHuEPO treatment was more significant.