Bellamy Leeann M, Joanisse Sophie, Grubb Amanda, Mitchell Cameron J, McKay Bryon R, Phillips Stuart M, Baker Steven, Parise Gianni
Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
PLoS One. 2014 Oct 14;9(10):e109739. doi: 10.1371/journal.pone.0109739. eCollection 2014.
The extent of skeletal muscle hypertrophy in response to resistance training is highly variable in humans. The main objective of this study was to explain the nature of this variability. More specifically, we focused on the myogenic stem cell population, the satellite cell (SC) as a potential mediator of hypertrophy. Twenty-three males (aged 18-35 yrs) participated in 16 wk of progressive, whole body resistance training, resulting in changes of 7.9±1.6% (range of -1.9-24.7%) and 21.0±4.0% (range of -7.0 to 51.7%) in quadriceps volume and myofibre cross-sectional area (CSA), respectively. The SC response to a single bout of resistance exercise (80% 1RM), analyzed via immunofluorescent staining resulted in an expansion of type II fibre associated SC 72 h following exercise (pre: 11.3±0.9; 72 h: 14.8±1.4 SC/type II fibre; p<0.05). Training resulted in an expansion of the SC pool associated with type I (pre: 10.7±1.1; post: 12.1±1.2 SC/type I fibre; p<0.05) and type II fibres (pre: 11.3±0.9; post: 13.0±1.2 SC/type II fibre; p<0.05). Analysis of individual SC responses revealed a correlation between the relative change in type I associated SC 24 to 72 hours following an acute bout of resistance exercise and the percentage increase in quadriceps lean tissue mass assessed by MRI (r2 = 0.566, p = 0.012) and the relative change in type II associated SC following 16 weeks of resistance training and the percentage increase in quadriceps lean tissue mass assessed by MRI (r2 = 0.493, p = 0.027). Our results suggest that the SC response to resistance exercise is related to the extent of muscular hypertrophy induced by training.
在人类中，骨骼肌对阻力训练产生的肥大程度差异很大。本研究的主要目的是解释这种变异性的本质。更具体地说，我们聚焦于肌源性干细胞群体，即卫星细胞（SC），将其作为肥大的潜在介导因素。23名男性（年龄在18 - 35岁之间）参与了为期16周的渐进式全身阻力训练，训练后股四头肌体积和肌纤维横截面积（CSA）分别变化了7.9±1.6%（范围为 - 1.9 - 24.7%）和21.0±4.0%（范围为 - 7.0至51.7%）。通过免疫荧光染色分析，单次阻力运动（80% 1RM）后卫星细胞的反应显示，运动后72小时II型纤维相关卫星细胞数量增加（运动前：11.3±0.9；72小时：14.8±1.4个卫星细胞/II型纤维；p<0.05）。训练导致与I型纤维相关的卫星细胞池扩大（运动前：10.7±1.1；运动后：12.1±1.2个卫星细胞/I型纤维；p<0.05）以及II型纤维相关的卫星细胞池扩大（运动前：11.3±0.9；运动后：13.0±1.2个卫星细胞/II型纤维；p<0.05）。对个体卫星细胞反应的分析表明，急性阻力运动后24至72小时I型纤维相关卫星细胞的相对变化与通过MRI评估的股四头肌瘦组织质量的百分比增加之间存在相关性（r2 = 0.566，p = 0.012），以及16周阻力训练后II型纤维相关卫星细胞的相对变化与通过MRI评估的股四头肌瘦组织质量的百分比增加之间存在相关性（r2 = 0.493，p = 0.027）。我们的结果表明，卫星细胞对阻力运动的反应与训练诱导的肌肉肥大程度相关。
