大鼠脊髓损伤后线粒体代谢功能和还原型谷胱甘肽水平的变化

目的 探讨大鼠脊髓损伤后伤段脊髓线粒体代谢功能和还原型谷胱甘肽(GSH)水平的变化.方法 取48只SD大鼠,随机分为假手术组(对照组)和脊髓损伤组(SCI组),每组又分为处理后6、12、24 h 3个时相组,每个时相组8只,分别提取伤段脊髓的线粒体,测定线粒体呼吸功能呼吸Ⅲ态(R3)、呼吸Ⅳ态(R4)、呼吸控制率(RCR)及磷氧比(P/O)值]、三磷酸腺苷酶(ATPase)活性(Na+、K+-ATP酶和Ca2+、Mg2+-ATP酶活性)及GSH的变化.结果 SCI组在伤后6、12、24 h伤段脊髓线粒体的R3、RCR及P/O均显著低于对照组,R4显著高于对照组,差异有统计学意义(P＜0.05).SCl组Na+、K+-ATP酶和Ca2+、Mg2+-ATP酶较对照组明显降低,伤后6 h急剧下降,12 h后稍有代偿性升高,24 h后又下降,与对照组比较差异有统计学意义(P＜0.05).GSH水平SCI组与对照组相比明显降低,以伤后12 h最为明显,差异有统计学意义(P＜0.05).结论 脊髓损伤后伤段脊髓线粒体的呼吸功能、ATPase酶活性及GSH水平明显下降,说明脊髓损伤后线粒体能量代谢功能和自由基清除能力均受到明显损害.

Changes in metabolic function of mitochondria and reduced glutathione hormone after spinal cord injury in rates

Objective To study the changes in metabolic function of mitochondria and reduced glutathione hormone (GSH) after spinal cord injury (SCI) in rats.Methods Forty-eight adult SD rats were randomized into 2 even groups (control versus SCI) .SCI models were created using modified Allen' s method.In each group, mitochondria were extracted from the impaired spinal cords using Estabrook's method at 6, 12 and 24 hours after treatment (8 each time).Respiratory function of the mitochondria (including R3,R4, RCR and P/O), ATPase activities (including Na+/K+ ATPase and Ca2+/Mg2+ ATPase), and GSH levels were measured.Results The R3, RCR and P/O of the mitochondria were significantly lower at 6,12 and 24 hours after treatment in the SCI group than in the control group ( P ＜ 0.05), but the R4 was significantly higher ( P ＜ 0.05).The ATPase activities decreased rapidly at 6 hours, increased at 12 hours,but decreased again at 24 hours in the SCI group.Compared with the control group, the ATPase activities were significantly lower in the SCI group( P ＜ 0.05) .The GSH levels were significantly decreased in the SCI group, especially at 12 hours, compared with the control group( P ＜0.05). Conclusion Since the respiratory function, ATPase activities and GSH levels of mitochondria are significantly reduced after SCI, the metabolism of mitochondrial energy and the ability of the mitochondria to clear free radicals have been severely damaged.