运动延缓衰老的可能机理:活性氧生成对线粒体膜通透性转换的作用

A Possible Mechanism for Delaying Aging Process through Aerobic Exercise: Effects of Mitochondrial ROS Generation on Membrane Permeability Transition

目的 :以游泳训练为有氧运动模型 ,观察运动对衰老大鼠肝脏线粒体活性氧 (ROS)产生的影响及ROS对线粒体膜通透性转换 (MPT)的作用 ,以探讨运动延缓衰老的线粒体膜分子机理。方法 :1 2只SD大鼠随机分为衰老对照组 (C ,n =6)和衰老训练组 (T ,n =6) ;测定肝脏线粒体ROS生成、MDA含量和MPT。结果 :T组肝脏线粒体ROS生成和MDA含量均显著低于C组 (分别P <0 .0 5和P <0 .0 0 5 ) ;T组线粒体膜通透性转换孔 (PTP)半时开放时间较C组延长 ,即对Ca2 + 的敏感性降低 (P <0 .0 5 )。线粒体PTP半时开放时间与ROS生成和MDA含量呈负相关 (分别为r=-0 .494和r=-0 .479,均P <0 .0 0 1 )。结论 :有氧运动训练可能通过降低衰老组织线粒体ROS产生和减轻氧化损伤 ,而降低线粒体PTP开放的敏感性。

Aims Using the swimming model, the research focused on the effect of aerobic training on reactive oxygen species (ROS) generation rate of liver mitochondria and the effect of ROS on mitochondrial membrane permeability transition (MPT) in aging rats. Methods SD rats were randomly divided into two groups: Aging Control Group(C, n=6) and Aging Training Group (T, n=6). The following parameters were determined: (1) ROS by fluorometric probe; (2) the malondialdehyde (MDA) by TBA; (3) the sensitivity of mitochondria permeability transition pore (PTP) to Ca 2+ . Results The liver mitochondrial ROS generation and MDA content in training group were significant lower than those in aging control (P<0.05 and P<0.005, respectively). The T1/2 of the PTP opening in training group markedly prolonged compared with that in control (P<0.05), which means the decrease of the sensitivity of PTP to Ca 2+ . There was negative relationship of T1/2 of the PTP opening to ROS generation and MDA content(r=-0.494 and r=-0.479,P<0.001, respectively). Conclusions The present research indicated that the aerobic training might decrease the sensitivity of PTP to Ca 2+ through reducing both mitochondrial ROS generation and the oxidative damage.