Institute for Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
J Physiol. 2012 Sep 1;590(17):4351-61. doi: 10.1113/jphysiol.2012.237008. Epub 2012 Jul 16.
Low-load resistance training with blood flow restriction has been shown to elicit substantial increases in muscle mass and muscle strength; however, the effect on myogenic stem cells (MSCs) and myonuclei number remains unexplored. Ten male subjects (22.8 ± 2.3 years)performed four sets of knee extensor exercise (20% 1RM) to concentric failure during bloodflow restriction (BFR) of the proximal thigh (100 mmHg), while eight work-matched controls(21.9 ± 3.0 years) trained without BFR (control, CON). Twenty-three training sessions were performed within 19 days. Maximal isometric knee extensor strength (MVC) was examined pre- and post-training, while muscle biopsies were obtained at baseline (Pre), after 8 days intervention(Mid8) and 3 (Post3) and 10 days (Post10) post training to examine changes in myofibre area (MFA), MSC and myonuclei number. MVC increased by 7.1% (Post5) and 10.6% (Post12)(P <0.001) with BFR training, while type I and II MFA increased by 38% (Mid8), 35 – 37%(Post3) and 31 – 32% (Post10) (P <0.001). MSCs per myofibre increased with BFR training from 0.10 ± 0.01 (Pre) to 0.38 ± 0.02 (Mid8), 0.36 ± 0.04 (Post3) and 0.25 ± 0.02 (Post10) (P <0.001). Likewise, myonuclei per myofibre increased from 2.49 ± 0.07 (Pre) to 3.30 ± 0.22(Mid8), 3.20 ± 0.16 (Post3) and 3.11 ± 0.11 (Post10), (P<0.01). Although MFA increased in CON at Mid8, it returned to baseline at Post3. No changes in MSC or myonuclei number were observed in CON. This study is the first to show that short-term low-load resistance exercise performed with partial blood flow restriction leads to marked proliferation of myogenic stem cells and resulting myonuclei addition in human skeletal muscle, which is accompanied by substantial myofibre hypertrophy.
低负荷阻力训练结合血流限制已被证明可显著增加肌肉质量和肌肉力量；然而，其对成肌干细胞（MSCs）和肌核数量的影响仍未得到探索。10 名男性受试者（22.8 ± 2.3 岁）在血流限制（BFR）近端大腿（100mmHg）的情况下进行了四组膝关节伸肌运动（20% 1RM）至向心衰竭，而 8 名工作匹配的对照组（21.9 ± 3.0 岁）在没有 BFR（对照，CON）的情况下进行训练。在 19 天内进行了 23 次训练。在训练前后检查最大等长膝关节伸肌力量（MVC），同时在基线（Pre）、8 天干预后（Mid8）和 3（Post3）和 10 天（Post10）后获得肌肉活检，以检查肌纤维面积（MFA）、MSC 和肌核数量的变化。BFR 训练后，MVC 增加了 7.1%（Post5）和 10.6%（Post12）（P <0.001），而 I 型和 II 型 MFA 增加了 38%（Mid8）、35-37%（Post3）和 31-32%（Post10）（P <0.001）。BFR 训练后，每根肌纤维的 MSC 增加，从 0.10 ± 0.01（Pre）增加到 0.38 ± 0.02（Mid8）、0.36 ± 0.04（Post3）和 0.25 ± 0.02（Post10）（P <0.001）。同样，每根肌纤维的肌核也从 2.49 ± 0.07（Pre）增加到 3.30 ± 0.22（Mid8）、3.20 ± 0.16（Post3）和 3.11 ± 0.11（Post10）（P <0.01）。尽管 CON 在 Mid8 时 MFA 增加，但在 Post3 时恢复到基线。CON 中未观察到 MSC 或肌核数量的变化。这项研究首次表明，短期低负荷阻力运动结合部分血流限制可导致人类骨骼肌中成肌干细胞的显著增殖和随之而来的肌核增加，同时伴有肌纤维明显肥大。
