甲氨蝶呤对大鼠脊髓挫伤急性期氧化损伤相关蛋白的影响

Effect of methotrexate on spinal cord contusion-induced protein related with oxidative damage in rats at acute stage

目的：观察甲氨蝶呤（methotrexate,MTX）对大鼠脊髓挫伤急性期氧化损伤相关蛋白的影响,探讨其神经保护机制。方法：采用连有PinPoint TM精密接触传感器的BenchmarkTM立体定位颅脑撞击器制备脊髓挫伤大鼠模型。伤后30min,治疗组皮下注射MTX（0.5mg/kg,按体质量计）,对照组和假手术组注射等量生理盐水。术后1、3、6、12、24、48、72h进行动物采血和组织取材。采用酶联免疫吸附法检测血浆3-硝基酪氨酸（3-nitrotyrosine,3-NT）的含量以及损伤组织晚期氧化蛋白产物（advanced oxidation protein products,AOPP）和蛋白羰基（protein carbonyl）的含量。结果：术后各时间点,假手术组血浆中3-NT的含量以及组织中AOPP和蛋白羰基的含量均低于对照组。术后12～72h,治疗组血浆中3-NT含量均显著低于对照组（P〈0.05）。术后24~72h,治疗组组织中AOPP含量均显著低于对照组（P〈0.05）。但是,术后各时间点损伤组织中蛋白羰基的含量两组差异均无统计学意义。结论：MTX阻止脊髓继发性损伤可能与减少氧化损伤相关蛋白的形成有关。

AIM： To examine the effect of methotrexate on spinal cord contusion-induced protein related with oxidative damage in rats at acute stage and to explore its neuroprotective mechanism. METHODS： Rat spinal cord contu- sion model was duplicated by a BenchmarkTM stereotaxic cortical impactor which connected with PinPoint.9 precision contact sensor. At posttraurnatic 30 rain, Treatment group was subcutaneously administrated methotrexate （0.5 mg/kg, according to the weight） ,Control group and Sham group were injected the same volume of physiological saline. At posttraumatic 1,3,6, 12,24,48,72 h, blood and tissue samples were collected. ELISA method was used to determine the content of 3-nitrotyrosine （3-NT） in plasma, advanced oxidation protein products （AOPP） and protein carbonyl in injuried tissue. RE- SULTS：At all the time point after surgery, the contents of 3-NT, AOPP and protein carbonyl in Treatment group were lower than those in Con- trol group. Post-traumatic 12h to 72 h, the con- tents of 3-NT in Treatment group were signifi- cantly lower than those in Control group （P〈 0.05）. Post-traumatic 24 h to 72 h, the contents of AOPP in Treatment group were significantly lower than those in Control group （P〈0.05）. However, the content of protein carbonyl at each time point had no statistical significance be- tween the two groups. CONCLUSION： The role of Methotrexate in preventing the secondary spi- nal cord injury may be retated to reducing the formation of protein related with oxidative dam- age.