Early- and later-phases satellite cell responses and myonuclear content with resistance training in young men

Felipe Damas, Cleiton A. Libardi, Carlos Ugrinowitsch, Felipe C. Vechin, Manoel E. Lixandrao, Tim Snijders, Joshua P. Nederveen, Aline V. Bacurau, Patricia Brum, Valmor Tricoli, Hamilton Roschel, Gianni Parise*, Stuart M. Phillips

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

27 Citations (Web of Science)

Abstract

Satellite cells (SC) are associated with skeletal muscle remodelling after muscle damage and/or extensive hypertrophy resulting from resistance training (RT). We recently reported that early increases in muscle protein synthesis (MPS) during RT appear to be directed toward muscle damage repair, but MPS contributes to hypertrophy with progressive muscle damage attenuation. However, modulations in acute-chronic SC content with RT during the initial (1st-wk: high damage), early (3rd-wk: attenuated damage), and later (10th-wk: no damage) stages is not well characterized. Ten young men (27 +/- 1 y, 23.6 +/- 1.0 kg.m(-2)) underwent 10-wks of RT and muscle biopsies (vastus-lateralis) were taken before (Pre) and post (48h) the 1st (T1), 5th (T2) and final (T3) RT sessions to evaluate fibre type specific SC content, cross-sectional area (fCSA) and myonuclear number by immunohistochemistry. We observed RT-induced hypertrophy after 10-wks of RT (fCSA increased similar to 16% in type II, P < 0.04; similar to 8% in type I [ns]). SC content increased 48h post-exercise at T1 (similar to 69% in type I [P = 0.014]; similar to 42% in type II [ns]), and this increase was sustained throughout RT (pre T2: similar to 65%, similar to 92%; pre T3: similar to 30% [ns], similar to 87%, for the increase in type I and II, respectively, vs. pre T1 [P < 0.05]). Increased SC content was not coupled with changes in myonuclear number. SC have a more pronounced role in muscle repair during the initial phase of RT than muscle hypertrophy resulted from 10-wks RT in young men. Chronic elevated SC pool size with RT is important providing proper environment for future stresses or larger fCSA increases.
Original languageEnglish
Article number0191039
Number of pages12
JournalPLOS ONE
Volume13
Issue number1
DOIs
Publication statusPublished - 11 Jan 2018

Keywords

  • SKELETAL-MUSCLE REGENERATION
  • PROTEIN-SYNTHESIS
  • LENGTHENING CONTRACTIONS
  • DISUSE ATROPHY
  • OLDER MEN
  • EXERCISE
  • HYPERTROPHY
  • FIBERS
  • INCREASES
  • MECHANISM

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