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Non-linear myofilament elasticity in frog intact muscle fibres.

Edman, Paul LU (2009) In Journal of Experimental Biology 212(Pt 8). p.1115-1119
Abstract
The aim of the present investigation was to elucidate the elastic properties of the myofilaments during tetanic activity in striated muscle. The study was carried out on intact single muscle fibres from the anterior tibialis muscle of Rana temporaria (2.0-2.5 degrees C). The instantaneous stiffness was measured as the change in force that occurred in response to a high-frequency (2-4 kHz) length oscillation while the fibre was released to shorten against a pre-set constant load that ranged between 40 and 70% of maximum tetanic force in different experiments. Measurements of fibre stiffness were carried out, at a given load, both at 2.20 mum sarcomere length (S(2.20)), i.e. at full overlap between the thick and thin filaments, and at 2.60... (More)
The aim of the present investigation was to elucidate the elastic properties of the myofilaments during tetanic activity in striated muscle. The study was carried out on intact single muscle fibres from the anterior tibialis muscle of Rana temporaria (2.0-2.5 degrees C). The instantaneous stiffness was measured as the change in force that occurred in response to a high-frequency (2-4 kHz) length oscillation while the fibre was released to shorten against a pre-set constant load that ranged between 40 and 70% of maximum tetanic force in different experiments. Measurements of fibre stiffness were carried out, at a given load, both at 2.20 mum sarcomere length (S(2.20)), i.e. at full overlap between the thick and thin filaments, and at 2.60 mum sarcomere length (S(2.60)). The fact that the load on the fibre was constant during the stiffness measurements at the two sarcomere lengths implies that the stiffness of elastic elements, acting in series with the myofilaments, was constant at the two sarcomere lengths. The fibre stiffness was consistently lower at the extended sarcomere length, the S(2.60)/S(2.20) ratio ranging from 0.83 to 0.97 at the different loads investigated. Based on the S(2.60)/S(2.20) ratio, the compliance of the free portions of the thick and thin filaments could be calculated. The myofilament stiffness was found to increase progressively as the load was raised from 40 to 70% of maximum tetanic force. At 2.20 mum sarcomere length and at 40% of maximum load on the fibre, the calculated myofilament stiffness was approximately 2.5 times the maximum cross-bridge stiffness. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Experimental Biology
volume
212
issue
Pt 8
pages
1115 - 1119
publisher
The Company of Biologists Ltd
external identifiers
  • wos:000265270700011
  • pmid:19329745
  • scopus:63849269689
ISSN
1477-9145
DOI
10.1242/jeb.020982
language
English
LU publication?
yes
id
25919a79-4f5b-4edc-a223-e78d6a72a208 (old id 1367406)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/19329745?dopt=Abstract
date added to LUP
2009-04-02 15:46:26
date last changed
2017-07-09 04:32:59
@article{25919a79-4f5b-4edc-a223-e78d6a72a208,
  abstract     = {The aim of the present investigation was to elucidate the elastic properties of the myofilaments during tetanic activity in striated muscle. The study was carried out on intact single muscle fibres from the anterior tibialis muscle of Rana temporaria (2.0-2.5 degrees C). The instantaneous stiffness was measured as the change in force that occurred in response to a high-frequency (2-4 kHz) length oscillation while the fibre was released to shorten against a pre-set constant load that ranged between 40 and 70% of maximum tetanic force in different experiments. Measurements of fibre stiffness were carried out, at a given load, both at 2.20 mum sarcomere length (S(2.20)), i.e. at full overlap between the thick and thin filaments, and at 2.60 mum sarcomere length (S(2.60)). The fact that the load on the fibre was constant during the stiffness measurements at the two sarcomere lengths implies that the stiffness of elastic elements, acting in series with the myofilaments, was constant at the two sarcomere lengths. The fibre stiffness was consistently lower at the extended sarcomere length, the S(2.60)/S(2.20) ratio ranging from 0.83 to 0.97 at the different loads investigated. Based on the S(2.60)/S(2.20) ratio, the compliance of the free portions of the thick and thin filaments could be calculated. The myofilament stiffness was found to increase progressively as the load was raised from 40 to 70% of maximum tetanic force. At 2.20 mum sarcomere length and at 40% of maximum load on the fibre, the calculated myofilament stiffness was approximately 2.5 times the maximum cross-bridge stiffness.},
  author       = {Edman, Paul},
  issn         = {1477-9145},
  language     = {eng},
  number       = {Pt 8},
  pages        = {1115--1119},
  publisher    = {The Company of Biologists Ltd},
  series       = {Journal of Experimental Biology},
  title        = {Non-linear myofilament elasticity in frog intact muscle fibres.},
  url          = {http://dx.doi.org/10.1242/jeb.020982},
  volume       = {212},
  year         = {2009},
}