Endurance training facilitates myoglobin desaturation during muscle contraction in rat skeletal muscle.
Endurance training facilitates myoglobin desaturation during muscle contraction in rat skeletal muscle.
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DOI：
10.1038/srep09403
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发表时间：
2015-03-24
影响因子：
4.6
通讯作者：
Masuda K
中科院分区：
文献类型：
--
作者：
Takakura H;Furuichi Y;Yamada T;Jue T;Ojino M;Hashimoto T;Iwase S;Hojo T;Izawa T;Masuda K
在肌肉收缩开始时，肌红蛋白（Mb）立即将其结合的O2释放到线粒体。因此，细胞内氧张力（PmbO2）显著下降，以增加肌肉氧摄取（mO2）。然而，肌肉收缩过程中PmbO2的变化是否会调节mO2，以及耐力训练肌肉中Mb的O2释放率是否会增加，目前尚不清楚。因此，本研究的目的是确定耐力训练对肌肉收缩过程中Mb （SmbO2）和PmbO2氧饱和度动力学的影响。雄性Wistar大鼠进行为期4周的游泳训练（Tr组，每周6天，每天30分钟× 4组），体重负荷为体重的2%。训练结束后，在无血红蛋白介质灌注下，用近红外光谱测量肌肉收缩过程中的脱氧Mb动力学。在Tr组中，mo2峰值显著升高32%。虽然肌肉收缩时的PmbO2不影响耐力训练肌肉中mO2的增加，但由于最大肌拉张力时Mb浓度增加和SmbO2减少速度更快，Mb的O2释放率增加。这些结果表明，肌肉收缩过程中的Mb动力学是耐力训练肌肉中更快的氧动力学的促进因素。
At onset of muscle contraction, myoglobin (Mb) immediately releases its bound O2 to the mitochondria. Accordingly, intracellular O2 tension (PmbO2) markedly declines in order to increase muscle O2 uptake (mO2). However, whether the change in PmbO2 during muscle contraction modulates mO2 and whether the O2 release rate from Mb increases in endurance-trained muscles remain unclear. The purpose of this study was, therefore, to determine the effect of endurance training on O2 saturation of Mb (SmbO2) and PmbO2 kinetics during muscle contraction. Male Wistar rats were subjected to a 4-week swimming training (Tr group; 6 days per week, 30 min × 4 sets per day) with a weight load of 2% body mass. After the training period, deoxygenated Mb kinetics during muscle contraction were measured using near-infrared spectroscopy under hemoglobin-free medium perfusion. In the Tr group, the mO2peak significantly increased by 32%. Although the PmbO2 during muscle contraction did not affect the increased mO2 in endurance-trained muscle, the O2 release rate from Mb increased because of the increased Mb concentration and faster decremental rate in SmbO2 at the maximal twitch tension. These results suggest that the Mb dynamics during muscle contraction are contributing factors to faster O2 kinetics in endurance-trained muscle.
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影响因子：
3.8
作者：
Dash, RK;Bassingthwaighte, JB
通讯作者：
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