Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.
School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
Am J Physiol Cell Physiol. 2022 Dec 1;323(6):C1577-C1585. doi: 10.1152/ajpcell.00418.2022. Epub 2022 Oct 24.
Satellite cells (SCs) and ribosomes are key determinants of the skeletal muscle adaptive response. Both are thought to increase acutely after resistance exercise and chronically with resistance training. However, the acute SC and ribosome exercise response with prior aerobic conditioning is unknown. Fourteen young men and women underwent 6 wk of single-legged aerobic conditioning followed by an acute bout of 300 eccentric contractions on each leg. Muscle biopsies were taken from the vastus lateralis of the aerobically conditioned (AC) and the control (CTL) legs before (Pre), 24 (24 h), and 48 (48 h) h post-contractions. Pre-eccentric contractions, 45S pre-rRNA and 5.8S internal transcribed spacer (ITS) expression were lower in the AC leg compared with the CTL leg. SC content (PAX7 cells/100 fibers) in type I and mixed fibers showed a main effect of condition, where values were greater in the AC leg compared with the CTL. A main effect of condition for and mRNA expression was observed where expression was greater in the AC leg compared with the CTL. AC had greater RNA concentration and mRNA expression of and compared with CTL. Only the AC leg increased (Pre-24h) 45S pre-rRNA, 5.8S ITS, and 28S ITS following eccentric contractions. We discovered that aerobic conditioning increased type-I SC abundance and the acute increase in ribosome content following eccentric contractions.
卫星细胞 (SCs) 和核糖体是骨骼肌适应反应的关键决定因素。人们认为它们在抗阻运动后会急性增加，在抗阻训练后会慢性增加。然而，先前的有氧训练对急性 SC 和核糖体运动反应的影响尚不清楚。14 名年轻男女接受了 6 周的单腿有氧训练，然后对每条腿进行 300 次离心收缩的急性发作。在收缩前（Pre）、24 小时（24 h）和 48 小时（48 h）时，从有氧训练（AC）和对照（CTL）腿的外侧股采集肌肉活检。与 CTL 腿相比，AC 腿的预离心收缩、45S 前 rRNA 和 5.8S 内部转录间隔区（ITS）表达较低。I 型和混合纤维中的 SC 含量（PAX7 细胞/100 纤维）表现出条件的主要影响，其中 AC 腿的值大于 CTL 腿。还观察到 和 mRNA 表达的条件主要影响，其中 AC 腿的表达大于 CTL 腿。AC 腿的 RNA 浓度和 和 mRNA 表达均高于 CTL。只有 AC 腿在离心收缩后增加了（Pre-24h）45S 前 rRNA、5.8S ITS 和 28S ITS。我们发现，有氧训练增加了 I 型 SC 的丰度，并增加了离心收缩后核糖体含量的急性增加。
