A single bout of exercise activates skeletal muscle satellite cells during subsequent overnight recovery.

T. Snijders, L.B. Verdijk, M. Beelen, B.R. McKay, G. Parise, F. Kadi, L.J.C. van Loon

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Skeletal muscle satellite cell (SC) content has been reported to increase following a single bout of exercise. Data on muscle fibre type-specific SC content and/or SC activation status are presently lacking. The objective of the study was to determine the impact of a single bout of exercise on muscle fibre type-specific SC content and activation status following subsequent overnight recovery. Eight healthy men (age, 20 +/- 1 years) performed a single bout of combined endurance- and resistance-type exercise. Muscle biopsies were collected before and immediately after exercise, and following 9 h of postexercise, overnight recovery. Muscle fibre type-specific SC and myonuclear content and SC activation status were determined by immunohistochemical analyses. Satellite cell activation status was assessed by immunohistochemical staining for both Delta-like homologue 1 (DLK1) and Ki-67. Muscle fibre size and fibre area per nucleus were greater in type II compared with type I muscle fibres (P <0.05). At baseline, no differences were observed in the percentage of SCs staining positive for DLK1 and/or Ki67 between fibre types. No significant changes were observed in SC content following 9 h of postexercise, overnight recovery; however, the percentage of DLK1-positive SCs increased significantly during overnight recovery, from 22 +/- 5 to 41 +/- 5% and from 24 +/- 6 to 51 +/- 9% in the type I and II muscle fibres, respectively. No changes were observed in the percentage of Ki-67-positive SCs. A single bout of exercise activates both type I and II skeletal muscle fibre SCs within a single night of postexercise recovery, preceding the subsequent increase in SC content.

Original languageEnglish
Pages (from-to)762-773
Number of pages12
JournalExperimental Physiology
Volume97
Issue number6
DOIs
Publication statusPublished - Jun 2012

Keywords

  • OLDER MEN
  • LENGTHENING CONTRACTIONS
  • MYONUCLEAR ADDITION
  • ECCENTRIC EXERCISE
  • GENE-EXPRESSION
  • ELDERLY-MEN
  • HUMANS
  • HYPERTROPHY
  • STRENGTH
  • YOUNG

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