The Journal of General Physiology
Cell MicroControls
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text (PDF, 1110K)
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rall, J. A.
Right arrow Articles by Schottelius, B. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rall, J. A.
Right arrow Articles by Schottelius, B. A.
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  
What's this?
The Journal of General Physiology, Vol 62, 303-323, Copyright © 1973 by The Rockefeller University Press

ARTICLE

Energetics of Contraction in Phasic and Tonic Skeletal Muscles of the Chicken

Jack A. Rall 1 and B. A. Schottelius 1

1 From the Department of Physiology and Biophysics, The University of Iowa, Iowa City, Iowa 52242.

Dr. Rail's present address is the Department of Physiology, University of California at Los Angeles School of Medicine, Los Angeles, California 90024.

Comparative energetics of chicken latissimus dorsi muscles, tonic anterior (ALD) and phasic posterior (PLD), were investigated by measuring initial heat production. Heat components were analyzed in terms of the equation:

E = A + W + alphaF(DeltamacrL) + f(P, t)

As the muscles were stretched by increments, heat produced in isometric twitches and tetani decreased in a linear fashion. Two processes are involved: one tension independent, the activation heat, or A; and the other tension dependent, Wi + alphaF(DeltamacrL) + f(P, t). In twitches, A, per unit tension, is equivalent in the PLD and ALD. Tension-dependent heat, per unit tension, is greater in the PLD due to Wi; but tension-time-related heat, f(P, t), per unit tension, is similar in both muscles. In tetanic contractions, differences in A and f(P, t), per unit tension, are attributed to the greater Vmax in the PLD. The differences in the energetics of isometric contractions in the PLD and ALD, therefore, can be explained by inherent differences in tension development, compliance, and myosin and reticular ATPase activities. Data from isotonic twitches were quantified by means of the equivalent tension technique. Both muscles exhibited an extra heat associated with shortening, alphaF(DeltamacrL). In the PLD, the ratio alphaF/Pot is greater; it is load independent and frac12 the value of a/Po in both muscles. Enthalpy efficiency, We + Wi/E, is comparable in both muscles. A Fenn effect is observed only when isotonic energy liberation is compared to a decreasing isometric energy expenditure base line.

Submitted on July 19, 1972


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    What's this?


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
S.-J. Zhang, D. C. Andersson, M. E. Sandstrom, H. Westerblad, and A. Katz
Cross bridges account for only 20% of total ATP consumption during submaximal isometric contraction in mouse fast-twitch skeletal muscle
Am J Physiol Cell Physiol, July 1, 2006; 291(1): C147 - C154.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents