大鼠脊髓损伤后局部线粒体呼吸功能的变化

目的:探讨甲基强的松龙对大鼠脊髓损伤后局部线粒体呼吸功能的影响。方法:54只SD大鼠,随机分组为:假手术(对照组)、脊髓损伤(SCI组)和甲基强的松龙治疗(MP组),每组又分为处理后6h、12h、24h三个时相组,每组6只,采用Allen's打击法造成脊髓损伤模型,在各时相提取伤段脊髓线粒体,测定线粒体呼吸Ⅲ态(R3)、Ⅳ态(R4)、呼吸控制率(RCR)、磷氧比(P/O)。结果:SCI组在伤后6h、12h和24h的R3、RCR和P/O显著低于对照组,R4显著高于对照组,有统计学意义(P<0.01);MP组伤后6h和12hR3、RCR和P/O高于SCI组,R4低于SCI组,有统计学意义(P<0.01);MP组R3、R4和RCR在6h和12h时相与对照组之间无明显差异,24h时相R3、RCR和P/O低于正常对照组,有显著差异(P<0.05)。结论:脊髓损伤后局部线粒体呼吸功能明显受到影响,线粒体内膜通透性增加,线粒体氧化磷酸化的偶联程度明显受到抑制。早期使用甲基强的松龙可明显改善线粒体的呼吸功能,保护伤段脊髓线粒体的稳定性。

Change of mitochondrial respiratory function in local spinal cord after spinal cord injury in rats

Objective: To detect the change of the mitochondrial respiratory function in the local spinal cord after spinal cord injury(SCI)in rats.Methods:The SCI model in adult SD rats was built based on modified Allen's method.Mitochondria ere extracted from injuried spinal cord tissue by using modified Estabrook's method at 6h,12h and 24h after SCI.Then respiratory functions,including R3,R4,RCR and P/O were measured.Results:The results revealed that R3,RCR and P/O of injuried spinal cord mitochondria decreased significantly after injury compared to the normal control group(P<0.01) at 6h,12h and 24h after SCI,but the results of R4 increased evidently(P<0.01).In MP group,R3、RCR and P/O of injuried spinal cord mitochondria significantly increased after injury compared to SCI group(P<0.01),but R4 decreased evidently(P<0.01).There was significant difference between MP group and SCI group(P <0.01).Conclusion :The results suggest that mitochondrial respiratory function changes significantly after SCI.Early-stage methylprednisolone treatment could improve mitochondrial respiratory function in rats after SCI.