Sharifimajd Babak, Stålhand Jonas
Division of Mechanics, Department of Management and Engineering, The Institute of Technology, Linköping University, 581 83 Linköping, Sweden.
Division of Mechanics, Department of Management and Engineering, The Institute of Technology, Linköping University, 581 83 Linköping, Sweden.
J Theor Biol. 2014 Aug 21;355:1-9. doi: 10.1016/j.jtbi.2014.03.016. Epub 2014 Mar 19.
The main focus in most of the continuum based muscle models is the mechanics of muscle contraction while other physiological processes governing muscle contraction, e.g., cell membrane excitation and activation, are ignored. These latter processes are essential to initiate contraction and to determine the amount of generated force, and by excluding them, the developed model cannot replicate the true behavior of the muscle in question. The aim of this study is to establish a thermodynamically and physiologically consistent framework which allows us to model smooth muscle contraction by including cell membrane excitability and kinetics of myosin phosphorylation, along with dynamics of smooth muscle contraction. The model accounts for these processes through a set of coupled dissipative constitutive equations derived by applying first principles. To show the performance of the derived model, it is evaluated for two different cases: a chemo-mechanical study of pig taenia coli cells where the excitation process is excluded, and an electro-chemo-mechanical study of rat myometrium. The results show that the model is able to replicate important aspects of the smooth muscle excitation-contraction process.
大多数基于连续体的肌肉模型主要关注肌肉收缩的力学原理，而忽略了其他控制肌肉收缩的生理过程，例如细胞膜的兴奋和激活。后述这些过程对于启动收缩和确定产生的力的大小至关重要，并且通过排除它们，所开发的模型无法复制所研究肌肉的真实行为。本研究的目的是建立一个热力学和生理学上一致的框架，使我们能够通过纳入细胞膜兴奋性、肌球蛋白磷酸化动力学以及平滑肌收缩动力学来对平滑肌收缩进行建模。该模型通过应用第一原理推导的一组耦合耗散本构方程来解释这些过程。为了展示所推导模型的性能，对两种不同情况进行了评估：对猪结肠带细胞进行的化学 - 力学研究（其中排除了兴奋过程），以及对大鼠子宫肌层进行的电 - 化学 - 力学研究。结果表明，该模型能够复制平滑肌兴奋 - 收缩过程的重要方面。
