Greater Oxidative Capacity in Primary Myotubes from Endurance-trained Women.
Greater Oxidative Capacity in Primary Myotubes from Endurance-trained Women.
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DOI：
10.1249/mss.0000000000001352
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发表时间：
2017-11
影响因子：
4.1
通讯作者：
Funai K
中科院分区：
文献类型：
--
作者：
Heden TD;Ryan TE;Ferrara PJ;Hickner RC;Brophy PM;Neufer PD;McClung JM;Funai K
运动训练促进骨骼肌线粒体生物合成和最大耗氧量的增加。初级肌管保留了体内观察到的一些代谢特性，但尚不清楚这是否包括运动诱导的线粒体适应。这项研究的目的是测试接受运动训练的女性的初级肌管是否比未经训练的女性具有更高的线粒体含量和最大耗氧量。6名受过训练的高加索妇女和9名未受过训练的高加索妇女参加了这项研究。取右腿股外侧肌组织，分离出原代肌细胞。对受训和未受训的女性的骨骼肌和初级肌管的最大呼吸频率、线粒体mRNA和蛋白质含量以及琥珀酸脱氢酶活性进行了测量。与未经训练的女性相比，受训女性的最大全身耗氧量(+18%，P=0.03)、近红外光谱测定的活体最大骨骼肌氧化量(+48%，P<；0.01)和通透性肌纤维的最大耗氧量(+38%，P=0.02)都较高，这与肌肉线粒体酶的蛋白质水平较高相吻合。训练女性的初级肌管的最大耗氧量较高(+38%，P=0.03)，表明运动诱导的代谢编程的某些元素在体外仍然存在。与这一观点一致的是，受过训练的女性的肌管除了线粒体酶的蛋白质水平更高外，还具有更高的线粒体生物发生转录调节器的mRNA水平。这些数据表明存在一种“运动代谢计划”，与未经训练的人相比，从运动训练的个体分离的初级肌管显示出更多的线粒体含量和氧化能力。这些肌管可能是研究人类骨骼肌运动适应相关分子机制的有用模型。
Exercise training promotes skeletal muscle mitochondrial biogenesis and an increase in maximal oxygen consumption. Primary myotubes retain some metabolic properties observed in vivo but it is unknown whether this includes exercise-induced mitochondrial adaptations. The goal of this study was to test if primary myotubes from exercise-trained women have higher mitochondrial content and maximal oxygen consumption compared to untrained women. Six trained and nine untrained Caucasian women participated in this study. Muscle biopsies from the vastus lateralis muscle of the right leg were obtained and primary muscle cells were isolated. Maximal respiration rates, mitochondrial mRNA and protein content, and succinate dehydrogenase activity were measured in skeletal muscle and primary myotubes from trained and untrained women. Trained women, compared to untrained women, had higher maximal whole-body oxygen consumption (+18%, P = 0.03), in vivo maximal skeletal muscle oxidative capacity measured with near infrared spectroscopy (+48%, P < 0.01), and maximal oxygen consumption in permeabilized muscle fibers (+38%, P = 0.02), which coincided with higher protein levels of muscle mitochondrial enzymes. Primary myotubes from trained women had higher maximal oxygen consumption (+38%, P = 0.03) suggesting that some elements of exercise-induced metabolic programming persists ex vivo. Consistent with this idea, myotubes from trained women had higher mRNA levels of transcriptional regulators of mitochondrial biogenesis in addition to higher protein levels of mitochondrial enzymes. These data suggest the existence of an “exercise metabolic program”, where primary myotubes isolated from exercise-trained individuals exhibit greater mitochondrial content and oxidative capacity compared to untrained individuals. These myotubes may be a useful model to study molecular mechanisms relevant to exercise adaptations in human skeletal muscle.