甲泼尼龙对急性脊髓爆震伤后脊髓继发性损伤的影响

The effect of methylpredulsolone on spinal cord lesion secondary to blast injury

目的探讨甲泼尼龙（MP）对脊髓爆震性损伤早期救治的效果及其机制。方法家兔36只，随机分为三组：对照组、损伤组和MP组，每组12只。除对照组外，其他两组建立局限性脊髓爆震性损伤模型，损伤组仅给予生理盐水注射，MP组致伤后立即给予MP治疗。于伤后6、12、24h取血液标本和损伤段脊髓标本，测定血液和脊髓组织中SOD、MDA和Ca^＋的含量变化情况，同时观察损伤段脊髓组织的病理变化。结果损伤组血液标本和脊髓组织中MDA、Ca^＋升高，SOD浓度下降，与对照组比较差异有统计学意义（P〈0．01）。与损伤组比较，MP组能明显降低脊髓爆震伤后血液标本和损伤脊髓中MDA、Ca^＋含量，防止SOD损失，差异有统计学意义（P〈0．01）。组织学观察可见损伤组伤后6h脊髓组织出现轻微坏死，24h出现不可逆性损伤，MP组脊髓组织坏死性改变较轻。结论急性脊髓爆震伤后立即应用MP冲击治疗，能够明显降低血清和脊髓组织中MDA、Ca^＋含量，提高SOD浓度，在一定程度上阻止继发性损伤的进一步发展。

Objective To investigate the effect of methylprednisolone（MP） in early treatment of blast injury to spinal cord and to explore its possible mechanism. Methods Thirty-six rabbits were randomly allocated into 3 groups： control, injury and MP treatment. Models of local blast injury to spinal cord were created according to our previously established methods in the injury and MP treatment groups. Samples of the blood and injured spinal cord were harvested at 6 h, 12 h and 24 h after injury. SOD, MDA and Ca^＋ levels in the blood and injured spinal cord were determined, and pathology of the injured spinal cord was observed. Results In the injury group, MDA and Ca^＋ in both blood and spinal cord increased significantly while SOD decreased, compared with those in the control group （ P 〈 0. 01 ） . These changes were markedly alleviated by immediate MP treatment （ P 〈 0. 01）. Mild necrosis in the injured tissue was observed 6 h after the injury, which progressed to irreversible damage 24 h after injury. MP treatment distinctly relieved the necrotic changes. Conclusion Since immediate application of MP in treatment of acute blast injury to spinal cord can markedly lower MDA and Ca^＋ levels but increase SOD concentration in both serum and spinal cord tissue, it may inhibit the progression of secondary injuries to some extent.