A non-isometric kinetic model for smooth muscle.
Yu, Sung-Nien, Patrick E. Crago, and Hillel J. Chiel.
Departments of Biomedical Engineering and Biology, Case Western
Reserve University, Cleveland, Ohio 44106
APStracts 3:0385C, 1996.
We have modeled the non-isometric contractile dynamics of smooth
muscle by modifying a 4-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 both 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 both isometric and non-isometric responses
of different kinds of smooth muscle, including vascular smooth
muscle, airway smooth muscle, molluscan catch muscle ABRM, and
Aplysia I2 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.
Received 11 December 1995; accepted in final form 7 October 1996.
APS Manuscript Number C742-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996