脊髓损伤后大鼠脊髓线粒体呼吸功能和游离Ca^(2+)含量的变化

Changes of spinal cord mitochondrial respiratory function and the contents of intramitochondria free calcium in experimental spinal cord injury model

目的:探讨脊髓损伤后大鼠伤段脊髓线粒体呼吸功能和线粒体内游离Ca2+含量的变化。方法:48只SD大鼠,随机分为对照组(假手术组,n=24)和脊髓损伤组(SCI组,n=24),每组又分为处理后6、12、24 h三时相组,每组8只,采用Allens’打击法造成大鼠脊髓损伤模型,在各时相提取伤段脊髓线粒体,用Clark氧电极法测定线粒体呼吸功能,根据线粒体呼吸耗氧量换算出呼吸Ⅲ态(R3)、呼吸Ⅳ态(R4)、呼吸控制率(RCR)、磷氧比值(P/O比值);用Reers法测定线粒体内游离Ca2+浓度。结果:SCI组在伤后6、12、24 h R3、RCR和P/O显著低于对照组,R4和线粒体游离Ca2+显著高于对照组,有极显著统计学意义(P<0.01)。结论:大鼠脊髓损伤后伤段脊髓线粒体呼吸功能明显下降,线粒体Ca2+内流明显增加。

Objective ：To study the changes of spinal cord mitchondrial respiratory function and the contents of intramitochondria free calcium in experimental spinal cord injury （SCI） model. Methods：Twenty-four SCI models in aduh SD rats were built based on modified Allen＇s method.Mitochondria was extracted from injuried spinal cord tissue by using modified Estabrook＇s method 6,12,24 h after SCI. Then the respiratory function,including R3,R4,RCR,P/O and the contents of intramitochondria free calcium were measured. Results：R3 ,RCR and P/O of injuried spinal cord mitochondria decreased significantly 6 h, 12 h and 24 h after SCI compared to the normal control group （P 〈 0.01）, but the contents of intra-mitochondria free calcium and R4 increased significantly （P 〈 0.01）. Conclusion ：The results suggest that mitochondrial respiratory function decreases significantly and the contents of intramitochondria free calcium increase significantly after SCI.