耐力训练女性的原代肌管具有更强的氧化能力。
Greater Oxidative Capacity in Primary Myotubes from Endurance-trained Women.
作者信息
Heden Timothy D, Ryan Terence E, Ferrara Patrick J, Hickner Robert C, Brophy Patricia M, Neufer P Darrell, McClung Joseph M, Funai Katsuhiko
机构信息
1East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC; 2Department of Kinesiology, East Carolina University, Greenville, NC; 3Human Performance Laboratory, East Carolina University, Greenville, NC; and 4Department of Physiology, East Carolina University, Greenville, NC.
出版信息
Med Sci Sports Exerc. 2017 Nov;49(11):2151-2157. doi: 10.1249/MSS.0000000000001352.
PURPOSE
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 with untrained women.
METHODS
Six trained and nine untrained white 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.
RESULTS
Trained women, compared with 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.
CONCLUSIONS
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 with untrained individuals. These myotubes may be a useful model to study molecular mechanisms relevant to exercise adaptations in human skeletal muscle.
目的
运动训练可促进骨骼肌线粒体生物合成并增加最大摄氧量。原代肌管保留了一些在体内观察到的代谢特性，但尚不清楚这是否包括运动诱导的线粒体适应性变化。本研究的目的是测试与未训练女性相比，来自运动训练女性的原代肌管是否具有更高的线粒体含量和最大摄氧量。
方法
6名经过训练的白种女性和9名未训练的白种女性参与了本研究。获取右腿股外侧肌的肌肉活检样本，并分离出原代肌肉细胞。测量了训练和未训练女性的骨骼肌和原代肌管中的最大呼吸速率、线粒体mRNA和蛋白质含量以及琥珀酸脱氢酶活性。
结果
与未训练女性相比，训练有素的女性具有更高的全身最大摄氧量（+18%，P = 0.03）、用近红外光谱测量的体内最大骨骼肌氧化能力（+48%，P < 0.01）以及通透化肌纤维中的最大摄氧量（+38%，P = 0.02），这与肌肉线粒体酶的蛋白质水平较高相一致。来自训练有素女性的原代肌管具有更高的最大摄氧量（+38%，P = 0.03），这表明运动诱导的代谢编程的某些元素在体外持续存在。与此观点一致的是，来自训练有素女性的肌管除了线粒体酶的蛋白质水平较高外，线粒体生物合成转录调节因子的mRNA水平也较高。
结论
这些数据表明存在一种“运动代谢程序”，即与未训练个体相比，从运动训练个体分离出的原代肌管表现出更大的线粒体含量和氧化能力。这些肌管可能是研究与人类骨骼肌运动适应性相关分子机制的有用模型。
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