HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 100/2/656    most recent 00663.2005v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Rader, E. P. Articles by Faulkner, J. A. Search for Related Content PubMed PubMed Citation Articles by Rader, E. P. Articles by Faulkner, J. A.

Recovery from contraction-induced injury is impaired in weight-bearing muscles of old male mice

¹Department of Biomedical Engineering and ²Institute of Gerontology, University of Michigan, Ann Arbor, Michigan

Submitted 3 June 2005 ; accepted in final form 19 October 2005

With aging, the skeletal muscles of humans sustain decreases of 30% in mass and maximum force. Contraction-induced injury may contribute to these declines. When a 225 lengthening contraction protocol (LCP) was administered to small, non-weight-bearing muscles of mice, muscles of young/adult mice recovered completely, whereas those of old mice sustained permanent deficits of 20% in muscle mass and maximum force. Despite these observations, whether a large, frequently recruited, weight-bearing muscle sustains such permanent damage is not known. The hypothesis tested is that after a severe contraction-induced injury, large, weight-bearing muscles of old mice sustain permanent reductions in mass and force. The LCP was administered to plantar flexor muscles of adult and old, male C57BL/6 mice. At 3 days, 1 mo, and 2 mo after the LCP, maximum isometric forces were measured, anesthetized mice were euthanized, and muscles were removed and weighed. Two months after the LCP, the muscles of the adult mice regained control values of mass and force, whereas for muscles of old mice the mass decreased by 24% and the maximum force decreased by 32%. We conclude that a severe contraction-induced injury to large, weight-bearing muscles of old mice causes permanent deficits in mass and force.

aging; plantar flexor muscles; lengthening contractions

This article has been cited by other articles:

				G. S. Lynch, J. A. Faulkner, and S. V. Brooks Force deficits and breakage rates after single lengthening contractions of single fast fibers from unconditioned and conditioned muscles of young and old rats Am J Physiol Cell Physiol, July 1, 2008; 295(1): C249 - C256. [Abstract] [Full Text] [PDF]

				E. P. Rader and J. A. Faulkner Effect of aging on the recovery following contraction-induced injury in muscles of female mice J Appl Physiol, September 1, 2006; 101(3): 887 - 892. [Abstract] [Full Text] [PDF]