Åstrand Laboratory, The Swedish School of Sport and Health Sciences, Stockholm, Sweden.
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Acta Physiol (Oxf). 2020 Jul;229(3):e13463. doi: 10.1111/apha.13463. Epub 2020 Mar 19.
The body responds to exercise training by profound adaptations throughout the cardiorespiratory and muscular systems, which may result in improvements in maximal oxygen consumption (VO peak) and mitochondrial capacity. By convenience, mitochondrial respiration is often measured at supra-physiological oxygen levels, an approach that ignores any potential regulatory role of mitochondrial affinity for oxygen (p50 ) at physiological oxygen levels.
In this study, we examined the p50 of mitochondria isolated from the Vastus lateralis and Triceps brachii in 12 healthy volunteers before and after a training intervention with seven sessions of sprint interval training using both leg cycling and arm cranking. The changes in p50 were compared to changes in whole-body VO peak.
We here show that p50 is similar in isolated mitochondria from the Vastus (40 ± 3.8 Pa) compared to Triceps (39 ± 3.3) but decreases (mitochondrial oxygen affinity increases) after seven sessions of sprint interval training (to 26 ± 2.2 Pa in Vastus and 22 ± 2.7 Pa in Triceps, both P < .01). The change in VO peak modelled from changes in p50 was correlated to actual measured changes in VO peak (R = .41, P = .002).
Together with mitochondrial respiratory capacity, p50 is a critical factor when measuring mitochondrial function, it can decrease with sprint interval training and should be considered in the integrative analysis of the oxygen cascade from lung to mitochondria.
人体通过心肺和肌肉系统的深刻适应来应对运动训练，这可能导致最大摄氧量（VO 峰值）和线粒体容量的提高。由于方便起见，线粒体呼吸通常在超生理氧水平下进行测量，这种方法忽略了生理氧水平下线粒体对氧亲和力（p50）的任何潜在调节作用。
在这项研究中，我们在 12 名健康志愿者进行了为期 7 次的冲刺间歇训练干预之前和之后，检查了来自股外侧肌和肱三头肌的分离线粒体的 p50，该干预使用腿部循环和手臂曲柄进行了 7 次冲刺间歇训练。将 p50 的变化与全身 VO 峰值的变化进行了比较。
我们在这里表明，分离的股外侧肌（40±3.8 Pa）和肱三头肌（39±3.3 Pa）的线粒体的 p50 相似，但在 7 次冲刺间歇训练后降低（线粒体氧亲和力增加）（股外侧肌为 26±2.2 Pa，肱三头肌为 22±2.7 Pa，均 P<.01）。从 p50 变化推断出的 VO 峰值变化与实际测量的 VO 峰值变化相关（R=0.41，P=0.002）。
与线粒体呼吸能力一起，p50 是测量线粒体功能的关键因素，它可以随着冲刺间歇训练而降低，在从肺部到线粒体的氧级联的综合分析中应考虑到这一点。
