Organizational Systems and Adult Health, University of Maryland School of Nursing, 655 West Lombard Street, Baltimore, Maryland 21201, USA.
Muscle Nerve. 2010 Oct;42(4):522-9. doi: 10.1002/mus.21724.
Although the production of reactive oxygen species (ROS) during muscle contractile activity has been linked to both positive and negative adaptive responses, the sites for ROS generation within working muscle are not clearly defined. We assessed cytosolic ROS production and mitochondrial redox potential with a targeted redox-sensitive green fluorescent protein during repetitive field stimulation of single mature myofibers. Cytosolic ROS production increased by 94%, an effect that was abolished by pretreatment with the reducing agent dithiothreitol. Mitochondrial redox potential was not altered during muscle contraction. In contrast, activity-dependent ROS production was ablated by an inhibitor of NADPH oxidase. We provide the first report on dynamic ROS production from mitochondria in single living myofibers and suggest that the mitochondria are not the major source of ROS during skeletal muscle contraction. Alternatively, our data support a role for NADPH oxidase-derived ROS during contractile activity.
虽然在肌肉收缩活动过程中产生的活性氧（ROS）与积极和消极的适应性反应都有关联，但工作肌肉中 ROS 产生的部位尚不清楚。我们在对单个成熟肌纤维进行重复场刺激时，使用靶向的氧化还原敏感绿色荧光蛋白来评估细胞浆 ROS 的产生和线粒体氧化还原电势。细胞浆 ROS 的产生增加了 94%，这个效应在用还原剂二硫苏糖醇预处理后被消除。在肌肉收缩过程中线粒体氧化还原电势没有改变。相比之下，NADPH 氧化酶抑制剂可以消除依赖于活动的 ROS 产生。我们首次报道了在单个活肌纤维中线粒体中动态产生 ROS，并且提示在线粒体不是在骨骼肌收缩过程中 ROS 的主要来源。或者，我们的数据支持 NADPH 氧化酶衍生的 ROS 在收缩活动中的作用。
