|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online September 9, 2003
Characterization of the passive component of force enhancement following active stretching of skeletal muscle
University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
* Author for correspondence (e-mail: walter{at}kin.ucalgary.ca)
Accepted 17 May 2003
The mechanisms causing the steady-state force enhancement following active skeletal muscle stretching are not well understood. Recently, we found direct evidence that part of the force enhancement is associated with the engagement of a passive component. In this study, we reproduced the conditions that give consistent passive force enhancement and evaluated the mechanical properties of this passive force enhancement so as to gain insight into its source. The three primary results were that (1) the passive force enhancement is long lasting (>25 s), (2) passive force enhancement was reduced in a dose-dependent manner by the amount of shortening preceding active muscle stretching, and (3) passive force enhancement could be abolished `instantaneously' by shortening-stretching the passive muscle by an amount equivalent to the active stretch magnitude. Together with the remaining results, we conclude that the source of the passive force enhancement must be arranged in parallel with the contractile force, it must consist of a viscoelastic molecular spring whose stiffness characteristic can be reset by shortening, and it must have a characteristic length that is governed by the length of the contractile components, possibly the sarcomeres. Based on these results, the molecular spring titin emerges as a possible candidate for the passive component of the steady-state force enhancement observed in this and previous studies.
Key words: passive force, skeletal muscle, stretching, titin, cross-bridge theory, sarcomere length, stability, molecular spring, calcium
This article has been cited by other articles:
|
|
 |
|
  V. Joumaa, D. E. Rassier, T. R. Leonard, and W. Herzog The origin of passive force enhancement in skeletal muscle Am J Physiol Cell Physiol, January 1, 2008; 294(1): C74 - C78. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. E. Rassier and W. Herzog Relationship between force and stiffness in muscle fibers after stretch J Appl Physiol, November 1, 2005; 99(5): 1769 - 1775. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Ishii, T. Watari, and T. Tsuchiya Enhancement of twitch force by stretch in a nerve-skeletal muscle preparation of the frog Rana porosa brevipoda and the effects of temperature on it J. Exp. Biol., December 15, 2004; 207(26): 4505 - 4513. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Fujita, D. Labeit, B. Gerull, S. Labeit, and H. L. Granzier Titin isoform-dependent effect of calcium on passive myocardial tension Am J Physiol Heart Circ Physiol, December 1, 2004; 287(6): H2528 - H2534. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Rassier and W. Herzog Active force inhibition and stretch-induced force enhancement in frog muscle treated with BDM J Appl Physiol, October 1, 2004; 97(4): 1395 - 1400. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Peterson, D. E. Rassier, and W. Herzog Force enhancement in single skeletal muscle fibres on the ascending limb of the force-length relationship J. Exp. Biol., July 15, 2004; 207(16): 2787 - 2791. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Rassier and W. Herzog Considerations on the history dependence of muscle contraction J Appl Physiol, February 1, 2004; 96(2): 419 - 427. [Abstract] [Full Text] [PDF]
|
|
