spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online March 27, 2009
Journal of Experimental Biology 212, 1115-1119 (2009)
Published by The Company of Biologists 2009
doi: 10.1242/jeb.020982
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Edman, K. A. P.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Edman, K. A. P.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Non-linear myofilament elasticity in frog intact muscle fibres

K. A. P. Edman

Department of Experimental Medical Science, Biomedical Centre, University of Lund, S-221 84 Lund, Sweden

e-mail: paul.edman{at}med.lu.se

Accepted 9 February 2009

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°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 µm sarcomere length (S2.20), i.e. at full overlap between the thick and thin filaments, and at 2.60 µm sarcomere length (S2.60). 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 S2.60/S2.20 ratio ranging from 0.83 to 0.97 at the different loads investigated. Based on the S2.60/S2.20 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 µm 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.

Key words: muscle fibre, striated muscle, myofilament elasticity, muscle mechanics, stiffness measurement


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?




© The Company of Biologists Ltd 2009