Faculty Collaboration Database

Contractile properties of rat, rhesus monkey, and human type I muscle fibers. Am J Physiol 1997 Jan;272(1 Pt 2):R34-42

Date

01/01/1997

Pubmed ID

9038988

DOI

10.1152/ajpregu.1997.272.1.R34

Scopus ID

2-s2.0-0031023305 (requires institutional sign-in at Scopus site)   42 Citations

Abstract

It is well known that skeletal muscle intrinsic maximal shortening velocity is inversely related to species body mass. However, there is uncertainty regarding the relationship between the contractile properties of muscle fibers obtained from commonly studied laboratory animals and those obtained from humans. In this study we determined the contractile properties of single chemically skinned fibers prepared from rat, rhesus monkey, and human soleus and gastrocnemius muscle samples under identical experimental conditions. All fibers used for analysis expressed type I myosin heavy chain as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Allometric coefficients for type I fibers from each muscle indicated that there was little change in peak tension (force/fiber cross-sectional area) across species. In contrast, both soleus and gastrocnemius type I fiber maximal unloaded shortening velocity (Vo), the y-intercept of the force-velocity relationship (Vmax), peak power per unit fiber length, and peak power normalized for fiber length and cross-sectional area were all inversely related to species body mass. The present allometric coefficients for soleus fiber Vo (-0.18) and Vmax (-0.11) are in good agreement with published values for soleus fibers obtained from common laboratory and domesticated mammals. Taken together, these observations suggest that the Vo of slow fibers from quadrupeds and humans scale similarly and can be described by the same quantitative relationships. These findings have implications in the design and interpretation of experiments, especially those that use small laboratory mammals as a model of human muscle function.

Author List

Widrick JJ, Romatowski JG, Karhanek M, Fitts RH

Author

Robert Fitts PhD Professor in the Biological Sciences department at Marquette University

MESH terms used to index this publication - Major topics in bold

Animals
Foot
Humans
Isotonic Contraction
Knee
Macaca mulatta
Male
Muscle Contraction
Muscle Fibers, Slow-Twitch
Muscle, Skeletal
Myosin Heavy Chains
Rats
Time Factors