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This Article Full Text Full Text (PDF) All Versions of this Article: 90/4/519    most recent expphysiol.2005.029850v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mattson, J. P Articles by Martin, J. C Search for Related Content PubMed PubMed Citation Articles by Mattson, J. P Articles by Martin, J. C Related Collections Muscle

¹ Department of Health and Exercise Science, Gustavus Adolphus College, St. Peter, MN, USA ² College of Health, University of Utah, Salt Lake City, UT, USA

Patients with COPD suffer from locomotory skeletal muscle contractile dysfunction. This may be due to the disease per se or as a result of some confounding factor. Therefore, the purpose of this investigation was to determine whether emphysema: (1) reduces force production; (2) increases fatigability; and (3) impairs the speed of recovery in locomotory skeletal muscle in an accepted animal model in which many confounding variables can be controlled. To explore this issue, in situ mechanical properties of gastrocnemius were measured in Syrian Golden hamsters 8 months after intratracheal instillation of either saline (control, n = 5) or elastase (emphysema, n = 7). Emphysema increased excised lung volume (80%; P < 0.01), increased fatigability (control, 25% reduction in maximal strength after 4 min of repeated contractions; emphysema, 55% reduction; P < 0.05) and decreased the recovery rate (half-times of recovery: control, 7 ± 7 s; emphysema, 92 ± 92 s; P < 0.05) of gastrocnemius muscle. In contrast, emphysema had no effect on maximal force, whether related to body mass or muscle mass, or force–velocity characteristics of gastrocnemius muscle. These data demonstrate that emphysema, independent of physical activity levels, pharmacological intervention, and/or nutritional status, can increase fatigability and impair the speed of recovery of locomotory skeletal muscle contractile function which may contribute to exercise intolerance of COPD patients.

(Received 7 January 2005; accepted after revision 28 February 2005; first published online 8 March 2005)
Corresponding author J. P. Mattson: 212C Lund Center, 800 West College Avenue, Gustavus Adolphus College, St. Peter, MN 56082, USA.  Email: jmattson{at}gac.edu