大剂量甲基强的松龙治疗脊髓损伤鼠的实验研究

目的 探讨大剂量泼尼松（MP）治疗脊髓损伤的可行性。方法 SD成年雌性大鼠78只，随机分成13组：即假损伤组；脊髓挫伤组（SCI组）及大剂量甲基强的松龙治疗组（MP组），再分为：1d组、3d组、7d组、14d组、21d组、28d组；用改良的Allen装置造成T12脊髓节段挫裂伤。在手术前及术后进行BBB（Basso，Beattie and Bresnahan）评分。术后立即采用大剂量冲击疗法，腹腔注射MP30mg／kg，伤后1h开始，按5．4mg／（k·h）计算23h总量，分4次腹腔注射，在不同时间点处死大鼠。取损伤节段上、下长约0．5cm脊髓连续冰冻切片，间隔取片后分别以抗神经丝蛋白、突触素抗体行免疫组化ABC染色。在光学显微镜下观察各组NF、SYP在SD大鼠脊髓的表达分布情况。结果 MP明显改善损伤脊髓的病理形态。7，14，21，28d时MP组NF染色轴突数目均明显高于SCI组。而灰度值均明显低于SCI组。MP治疗组较SCI组相同时间点神经学功能均有明显提高。结论 大剂量MP在脊髓损伤中后期明显促进其损伤后的再生，具有中远期疗效。

Experimental Study of Therapy Effects of Methylprednisolone on Spinal Cord Injury

Objective To observe the effects of high-dose methylprednisolone on expression of NF and SYP in injuried spinal cord, and to study the possible therapy in spinal cord injury. Methods 78 healthy adult female SD（sprague-dawley） rats mean weight （220 ± 20） g ], were divided into 13 groups at random： Control group, spinal cord injury groups and methylprednisolone groups （1 d group,3 d group,7 d group,14 d group,21 d group,28 d group） ;the spinal cord injury at T12 segment of rats was made with modified Allen apparatus. BBB graded everyday before and after operation. After SCI ,high-dose methylprednisolone（ 30 mg/kg） was immediately injected into abdominal cavity. One hour later,the 23-hour dose was calculated by 5.4 mg/（ kg · h）, and divided into four times for intraperitoneal injection. The rats were killed in different days. The fixed spinal cord segments（ the TI2 spinal cord segments） were taken out from the rats. These tissues were made into frozen sections in 25 μm thickness, taken one section every two. The immunohistochemical ABC method was applied to detect the distribution and expression of NF and SYP in spinal white and gray matter in different days after SCI. All data were analyzed by one-way anova,SNK-q test and paired-t test. Results The pathological changes of spinal cord were significantly improved in MP. The MP groups, number of NF positive axons was significantly higher than the SCI groups in 7,14,21,28 d, still to remain lower than control group. The gray scale of NF positive axons increased gradually in 1 d,3 d,7 d,and decreased in 14 d,21 d,28 d. The MP groups＇ gray scale of SYP positive ax- ons was significantly lower than the SCI groups＇ in 7, 14,21,28 d. The BBB scores of MP groups were significantly higher than the SCI groups＇, still to remain lower than control group. Conclusions After SCI, MP can not change the decomposition and reparation process of SC axons,but improve the regeneration of SC in midanaphase.