Satellite cell numbers in young and older men 24 hours after eccentric exercise

Authors

  • Hans C. Dreyer PhD,

    Corresponding author
    1. Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, USA
    • Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, USA
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  • Cesar E. Blanco PhD,

    1. Alfred E. Mann Institute for Biomedical Engineering, University of Southern California, Los Angeles, California, USA
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  • Fred R. Sattler MD,

    1. Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, USA
    2. Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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  • E. Todd Schroeder PhD,

    1. Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, USA
    2. Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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  • Robert A. Wiswell PhD

    1. Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, California, USA
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Abstract

We tested the hypothesis that the expansion of satellite cell numbers, 24 h after maximal eccentric knee extensor exercise, is blunted in older men. Muscle biopsies were obtained from the vastus lateralis of 10 young (23–35 years) and 9 older (60–75 years) men. Satellite cells were identified immunohistochemically using an antibody to neural cell adhesion molecule. After 92 maximal eccentric contractions, the mean number of satellite cells per muscle fiber increased to a greater extent among the young men (141%; P < 0.001) than older men (51%; P = 0.002) from preexercise levels. Similar results were obtained when satellite cells were expressed as a proportion of all sublaminar nuclei. We conclude that a single bout of maximal eccentric exercise increases satellite cell numbers in both age groups, with a significantly greater response among the young men. These data suggest that age-related changes in satellite cell recruitment may contribute to muscle regeneration deficits among the elderly. Muscle Nerve 2006

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