Testosterone administration to elderly men increases skeletal muscle strength and protein synthesis

Randall Urban, Y. H. Bodenburg, C. Gilkison, J. Foxworth, A. R. Coggan, R. R. Wolfe, A. Ferrando

Research output: Contribution to journalArticle

485 Scopus citations

Abstract

Aging men develop a significant loss of muscle strength that occurs in conjunction with a decline in serum testosterone concentrations. We investigated the effects of testosterone administration to six healthy men [67 ± 2 (SE) yr] on skeletal muscle protein synthesis, strength, and the intramuscular insulin-like growth factor I (IGF-I) system. Elderly men with serum testosterone concentrations of 480 ng/dl or less were given testosterone injections for 4 wk to produce serum concentrations equal to those of younger men. During testosterone administration muscle strength (isokinetic dynamometer) increased in both right and left hamstring and quadricep muscles as did the fractional synthetic rate of muscle protein (stable-isotope infusion). Ribonuclease protection assays done on total RNA from muscle showed that testosterone administration increased mRNA concentrations of IGF-I and decreased mRNA concentrations of insulin-like growth factor binding protein-4. We conclude that increasing testosterone concentrations in elderly men increases skeletal muscle protein synthesis and strength. This increase may be mediated by stimulation of the intramuscular IGF-I system.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume269
Issue number5 32-5
StatePublished - 1995

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Keywords

  • aging
  • insulin-like growth factor binding proteins
  • insulin-like growth factor I

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Physiology
  • Agricultural and Biological Sciences(all)

Cite this

Urban, R., Bodenburg, Y. H., Gilkison, C., Foxworth, J., Coggan, A. R., Wolfe, R. R., & Ferrando, A. (1995). Testosterone administration to elderly men increases skeletal muscle strength and protein synthesis. American Journal of Physiology - Endocrinology and Metabolism, 269(5 32-5).