甲泼尼龙对大鼠急性脊髓损伤后髓鞘碱性蛋白的作用研究

目的探讨大剂量甲泼尼龙(MP)对急性脊髓损伤(ASCI)后大鼠脊髓组织和血清中的髓鞘碱性蛋白(MBP)的影响。方法 60只雄性SD大鼠,随机分成A组(正常对照组)、B组(实验对照组)、C组(治疗组)三组,每组20只。A组单纯全椎板切除,不损伤脊髓;B、C组采用Allen's法制作T10脊髓损伤模型,C组首剂量以30 mg/kg甲泼尼龙尾静脉注射,余剂量以5.4 mg·kg-1·h-1,每4 h静脉给药一次,24 h给完,A、B组以生理盐水代替甲泼尼龙尾静脉注射,剂量同C组。术后24 h、48 h对A、B、C三组大鼠后肢运动功能行BBB评分;再在各时间点取受损节段脊髓行HE染色及免疫组化染色观察形态学变化和MBP在脊髓组织中的分布特点;同时应用RT-PCR方法测定各组相应时间点脊髓组织中MBP m RNA表达量;取血清应用ELISA方法检测各组中血清MBP含量。结果 C组大鼠在损伤后24 h、48 h后肢运动功能恢复程度显著高于B组,差异有显著性(P<0.01)。B、C组血清中的MBP蛋白浓度较A组均明显升高,而C组血清的MBP蛋白浓度显著低于B组,差异有显著性(P<0.01);C组脊髓组织中MBP表达高于B组,而低于A组,差异有显著性(P<0.01);C组MBP m RNA表达显著高于B组(P<0.01),而低于A组,差异有显著性(P<0.05)。结论大鼠急性脊髓损伤后血清中MBP显著升高,脊髓组织中MBP表达会降低,早期应用大剂量MP对脊髓急性损伤具有明显的保护作用。

The research of the effect of MP on the MBP of rats suffered from ASCI

ObjectiveTo study the effect of high-dose methylprednisolone （MP） on the myelin basic protein （MBP） in myoloid tissue and serum of rats suffered from acute spinal cord injury （ASCI）. MethodsSixty SD male rats were randomly divided into three different groups, each of which had 20 rats. They were group A （normal control group）, group B （control group）, and group C （treatment group）. Rats＇ spine in group A was merely respected by total laminectomy without any hurts to its spinal cord. Both group B and C were assigned to be evaluated by using ASCI model （T10） made by Allen＇s method. Rats in group C were injected the MP which amounted to 30 mg/kg at the beginning. However, the remaining were injected every 4 hours at the amount of 5.4 mg/kg each time. The same goes to group A and B, apart from that MP, which was replaced by normal saline instead. After 24 hours and 48 hours of the operation, the researcher evaluated its hind limb movement function of each group by virtue of BBB. And then analyzed the pathological changes and distribution feature of MBP by observing HE-staining and immunohistochemical staining of the injured spinal cord at different time point. Meanwhile, the researcher also measured the expression of MBP mRNA in each group by the method of RT-PCR at the correspondingtime point and inspected the expression of MBP of serum by the way of ELISA.Results After 24 hours and 48 hours of the operation, compared with group B, the rats＇ recovery degree of the hind limb movement function were obviously higher, the difference was significant （P〈0.001）, while the MBP of group B and C was much higher than that of group A, the difference was significant （P〈0.001）, besides, the expression of spinal cord tissue of group C was higher than group B （P〈0.05）, while lower than group A, however, the MBP in serum of rats in group C was obviously lower than that of group B, the difference was significant （P〈0.01）.ConclusionOnce suffered from ASCI, the rats＇ MBP in se