Myogenic, matrix and growth factor mRNA expression in human skeletal muscle: effect of contraction intensity and feeding

Research output: Contribution to journalArticlepeer-review

Authors

  • Jakob Agergaard
  • Søren Reitelseder
  • T.G. Pedersen
  • Simon Doessing
  • Peter Schjerling
  • Henning Langberg
  • Benjamin F Miller
  • P Aagaard
  • Michael Kjær

Colleges, School and Institutes

Abstract

INTRODUCTION: We examined short-term (3-hour) and long-term (12-week) training effects after heavy load [HL; 70% 1RM] and light load (LL; 16% 1RM) exercise. METHODS: mRNA expression of genes involved in skeletal muscle remodeling were analyzed and muscle activity (EMG measurements) was measured. RESULTS: Relative muscle activity differed between HL and LL resistance exercise, whereas median power frequency was even, suggesting an equal muscle-fiber-type recruitment distribution. mRNA expression of Myf6, myogenin, and p21 was mostly increased, and myostatin was mostly depressed by HL resistance exercise. No major differences were seen in atrophy-related genes between HL and LL resistance exercise. No changes were seen over 12-week training for any of the targets. CONCLUSIONS: Resistance exercise at LL and HL elevated the expression of genes involved in skeletal muscle hypertrophy, although the greatest response was from HL. However, no long-term effect from either LL or HL resistance exercise was seen on basal levels of the mRNA targets.

Details

Original languageEnglish
Pages (from-to)748-759
Number of pages12
JournalMuscle & Nerve
Volume47
Issue number5
Publication statusPublished - 20 Mar 2013