环孢素A对大鼠脑损伤后髓鞘碱性蛋白抗体及继发性脱髓鞘病变的影响

Cyciosporin A affects the level of anti-myelin basic protein in serum and myelinoclasis after rat brain trauma

目的研究环孢素A（CsA）对大鼠脑损伤后血清中髓鞘碱性蛋白抗体（Anti—MBP）及继发性脑干脱髓鞘病变程度的影响。方法SD大鼠77只按随机数字表法分为空白对照组（n=71、模型组（n=35）、CsA组（n=35）。后2组大鼠制作闭合性重型颅脑损伤模型，术后模型组大鼠持续腹腔注射0．9％生理盐水[5mg／（kg·d）]，CsA组大鼠腹腔注射5mg／mLCsA[5mg／（kg·d）】，于不同时间点（伤后1、4、10、20、30d）处死大鼠后采用ELLSA法检测血清MBP和Anti-MBP含量．Marchi锇酸染色法检测脑干脱髓鞘病变程度。结果与空白对照组比较，模型组大鼠伤后血清MBP、Anti-MBP含量升高，差异有统计学意义（P〈0．05）；与模型组同一时间点比较，CsA组大鼠血清MBP含量差异无统计学意义俨〉0．05），而伤后1d开始Anti—MBP含量降低、伤后4d开始变性髓鞘数量降低，差异有统计学意义俨〈0．05）；Pearson相关分析显示CsA组与模型组大鼠血清Anti—MBP含量与脑干变性髓鞘的数量呈正相关关系（r=0．959，P=0．000）。结论CsA可以干预脑组织损伤后大鼠的免疫系统，在一定程度上可以减少Anti-MBP的产生、减轻大鼠继发性脑干脱髓鞘病变的程度。

Objective To investigate the effect of cyclosporin A （CsA） on the level of anti-myelin basic protein （anti-MBP） in the serum and myelinoclasis in rat models after brain trauma. Methods Seventy-seven SD rats were randomized into blank control group （n=7）, model group （n=35） and CsA-treated group （n=35）. The 0.9% normal saline （5 mg/kg/d） was intraperitoneally injected into the model group and 5 mg/mL CsA （5 mg/kg/d） was injected into the CsA-treated group. Different time points （1, 4, 10, 20 and 30 d） after the brain trauma, the MBP content and anti-MBP titer in the serum were measured using enzyme-linked immunosorbent assay （ELISA） and the degree ofmyelinoclasis in the brain stem slices was assessed with Marchi＇s method. Results As compared with that in the blank control group, the MBP and Anti-MBP contents in the model group were significantly increased （P〈0.05）： anti-MBP in the serum and the degree ofmyelinoclasis in the brain stem were all significantly increased in the 4th d, both reaching their highest levels on 10th d. No significant differences of the MBP content in the serum between the CsA-treated group and the model group were found the same time points after the injury （P〉0.05）. However, lower level of anti-MBP in the serum 1 d after the injury and degree of myelinoclasis in the brain stem 4 d after the injury in the CsA-treated group were observed as compared with those in the model group （P〈0.05）. Statistical analysis showed an intimate positive correlation between anti-MBP titer in serum and the degree of myelinoclasis （r=0.959, P=0.000）. ConclusionCsA can affect the immune system to decrease the degree of myelinoclasis in the brain stem through decreasing the level ofanti-MBP in the serum of rat models after brain trauma.