Resistance to radial expansion limits muscle strain and work.
Resistance to radial expansion limits muscle strain and work.
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DOI：
10.1007/s10237-017-0909-3
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发表时间：
2017-10
影响因子：
3.5
通讯作者：
Eaton CE
中科院分区：
文献类型：
--
作者：
Azizi E;Deslauriers AR;Holt NC;Eaton CE
骨骼肌的胶原细胞外基质（ECM）具有传递力、保护敏感结构和产生被动张力以抵抗拉伸的功能。ECM的机械性能随着年龄、萎缩和神经肌肉病理学而变化，导致胶原蛋白的相对量增加和刚度增加。虽然许多研究都集中在肌肉纤维化对被动肌肉僵硬的影响，很少有人研究这些结构变化如何可能损害收缩性能。在这里，我们结合联合收割机的数学模型和实验操作，以研究ECM的机械性能的变化如何约束肌肉纤维和肌束的径向扩张能力，以及这种约束如何限制主动肌肉缩短。我们使用恒定体积、加压、纤维缠绕的圆柱体来模拟收缩肌肉和ECM之间的机械相互作用。我们的模型表明，随着ECM组成的肌肉横截面的比例增加，肌肉径向扩张的能力受到损害，这反过来又限制了肌肉缩短。在我们的实验中，我们在肌肉周围放置了一个物理约束，以限制收缩期间的径向扩张。我们的实验结果与模型预测一致，表明在相同的负荷和刺激条件下，限制径向扩张的肌肉缩短较少，产生的机械功较少。这项工作突出了骨骼肌内收缩组织和结缔组织结构之间的密切机械相互作用，并显示了偏离健康，良好的关系如何影响性能。
The collagenous extracellular matrix (ECM) of skeletal muscle functions to transmit force, protect sensitive structures, and generate passive tension to resist stretch. The mechanical properties of the ECM change with age, atrophy, and neuromuscular pathologies, resulting in an increase in the relative amount of collagen and an increase in stiffness. Although numerous studies have focused on the effect of muscle fibrosis on passive muscle stiffness, few have examined how these structural changes may compromise contractile performance. Here we combine a mathematical model and experimental manipulations to examine how changes in the mechanical properties of the ECM constrain the ability of muscle fibers and fascicles to radially expand and how such a constraint may limit active muscle shortening. We model the mechanical interaction between a contracting muscle and the ECM using a constant volume, pressurized, fiber-wound cylinder. Our model shows that as the proportion of a muscle cross section made up of ECM increases, the muscle’s ability to expand radially is compromised, which in turn restricts muscle shortening. In our experiments, we use a physical constraint placed around the muscle to restrict radial expansion during a contraction. Our experimental results are consistent with model predictions and show that muscles restricted from radial expansion undergo less shortening and generate less mechanical work under identical loads and stimulation conditions. This work highlights the intimate mechanical interaction between contractile and connective tissue structures within skeletal muscle and shows how a deviation from a healthy, well-tuned relationship can compromise performance.
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DOI：
10.1038/nrm3510
发表时间：
2013-02
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
2.5
作者：
Huijing, Peter A.;van de langenberg, Rolf W.;Baan, Guus C.
通讯作者：
Baan, Guus C.
DOI：
10.1098/rspb.2013.2914
发表时间：
2014-05-22
影响因子：
4.7
作者：
Azizi, E.
通讯作者：
Azizi, E.
影响因子：
3.4
作者：
Gillies, Allison R.;Lieber, Richard L.
通讯作者：
Lieber, Richard L.
影响因子：
3.3
作者：
Huijing, PA;Baan, GC
通讯作者：
Baan, GC