A nonisometric kinetic model for smooth muscle.
A nonisometric kinetic model for smooth muscle.
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平滑肌的非等距动力学模型。
DOI：
10.1152/ajpcell.1997.272.3.c1025
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Chiel,HJ
中科院分区：
文献类型：
--
作者：
Yu,SN;Crago,PE;Chiel,HJ
我们通过修改Hai和Murphy最初提出的肌动蛋白和肌球蛋白键的四态模型来模拟脊椎动物肌肉的等长收缩，从而模拟了平滑肌的非等长收缩动力学。该模型包括一个闩锁桥，它的循环速度比常规的交叉桥慢。我们将这一模型推广到描述脊椎动物和无脊椎动物平滑肌的钙调节过程。我们通过假设跨桥的键合率和解键率依赖于长度来增加长度动力学。跨桥长度分布的计算被简化为假设为高斯分布，就像Zahalak首先对骨骼肌所做的那样。为了验证该模型的性能，我们模拟了不同类型的平滑肌的等长和非等长反应，包括血管平滑肌、呼吸道平滑肌、软体动物的牵引肌(前筋膜回缩肌)和海兔I(2)肌。该模型捕捉了肌肉等长收缩后期的经济力量维持特性，以及对强加的延长和缩短运动的反应。
We have modeled the nonisometric contractile dynamics of smooth muscle by modifying a four-state model of actin and myosin bonds originally proposed by Hai and Murphy to simulate the isometric contractions of vertebrate smooth muscle. The model includes a latch bridge, which cycles more slowly than regular cross bridges. We generalized this model to represent the calcium-regulated processes of vertebrate and invertebrate smooth muscles. We added length dynamics by assuming length-dependent bonding and unbonding rates for the cross bridges. The calculation of the cross-bridge length distribution was simplified by assuming a Gaussian distribution, as first done by Zahalak for skeletal muscle. To test the performance of this model, we simulated isometric and nonisometric responses of different kinds of smooth muscle, including vascular smooth muscle, airway smooth muscle, molluscan catch muscle (anterior byssus retractor muscle), and Aplysia I(2) muscle. The model captures the economical force maintenance property at the later stages of isometric muscle contraction and responses to imposed lengthening and shortening movements.