Hysteresis in cross-bridge models of muscle.
Hysteresis in cross-bridge models of muscle.
复制标题
肌肉跨桥模型中的滞后现象。
DOI：
10.1039/b900551j
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Sun,SeanX
中科院分区：
文献类型：
--
作者：
Walcott,Sam;Sun,SeanX
如果一个动力系统的当前状态取决于它的历史，那么它就被称为具有滞后性。肌肉在恒定长度时表现出滞后性，如拉伸后残余力增强。对于残余力的增强，没有一个普遍接受的解释。在这里，我们研究了肌动蛋白和肌球蛋白之间相互作用的一个非常简单的动力学模型，肌球蛋白是参与肌肉收缩的两种主要蛋白质。我们证明了该模型在恒定力作用下表现出滞后现象。由于肌肉不是一个连续体，而是一组重复的元素，称为肌节，排列成一系列，我们对三个肌节进行模拟。这些模拟显示了恒定长度的磁滞。这一结果是第一次使用实验激励的动力学模型和多肌节模拟来证明残余力增强，而不考虑被动弹性元件、阻尼和/或力-长度关系。最后，我们建议进行一些实验来验证该模型的预测。如果这些实验支持该模型，理解多个肌节系统就变得很重要，因为它们的行为可能与目前大多数忽略肌节之间耦合的模拟非常不同。
A dynamical system is said to exhibit hysteresis if its current state depends on its history. Muscle shows hysteretic properties at constant length, such as residual force enhancement after stretch. There is no generally accepted explanation for residual force enhancement. Here we examine a very simple kinetic model for the interaction between actin and myosin, the two main proteins involved in muscle contraction. We demonstrate that this model shows hysteresis at constant force. Since muscle is not a continuum but rather a group of repeating elements, called sarcomeres, arranged in series, we perform simulations of three sarcomeres. These simulations show hysteresis at constant length. This result is the first time that residual force enhancement has been demonstrated using an experimentally motivated kinetic model and multi-sarcomere simulations without passive elastic elements, damping and/or force-length relationships. We conclude by suggesting some experiments to test the model’s predictions. If these experiments support the model, it becomes important to understand multiple sarcomere systems, since their behavior may be very different from most current simulations that neglect the coupling between sarcomeres.