The stiffness response of type IIa fibres after eccentric exercise-induced muscle damage is dependent on ACTN3 r577X polymorphism

Siacia Broos, Laurent Malisoux, Daniel Theisen, Ruud Van Thienen, Marc Francaux, Martine A. Thomis*, Louise Deldicque

*Corresponding author for this work

Research output: Contribution to journalArticleResearchpeer-review

6 Citations (Scopus)

Abstract

The aim of the study was to determine the effect of α-actinin-3 (ACTN3) deficiency (XX) on muscle damage induced by an eccentric exercise bout. In this purpose, 4 RR and 4 XX individuals performed an intensive eccentric knee flexion exercise on an isokinetic dynamometer. Muscle biopsies, blood and pain scores were taken before and after the exercise to determine the extent of the exercise-induced damage and the effect of the ACTN3 R577X polymorphism. Maximal isometric strength of the quadriceps and single fibre properties were compared before and after the exercise. The drop in maximal isometric strength of the quadriceps at 45° knee flexion following the eccentric exercise bout was on average 37% 24 h post-exercise. The decrease in force was also apparent in isolated type II a fibres (8%; P = 0.02), but not in type I fibres (P = 0.88). Creatine kinase and myoglobin plasma levels increased in all participants at least by 55% and 87%, respectively (P < 0.05). In addition, mRNA levels of markers for muscle regeneration and muscle remodelling increased after the eccentric exercise (P < 0.05), however, independently from ACTN3 R577X genotype. The mRNA level of nuclear factor of activated T-cells 1 (NFATc1) decreased after the eccentric exercise only in XX genotypes (P < 0.05). The stiffness of type II a , but not type I muscle fibres increased only in RR individuals after the eccentric exercise (P < 0.05). While no major effect of α-actinin-3 deficiency on susceptibility to muscle damage was found acutely, the increased stiffness response in fast RR fibres might be a protection mechanism from muscle damage during a subsequent eccentric exercise bout.

Original languageEnglish
Pages (from-to)480-489
Number of pages10
JournalEuropean Journal of Sport Science
Volume19
Issue number4
DOIs
Publication statusPublished - 21 Apr 2019

Keywords

  • Actinin-3
  • human skeletal muscle
  • isolated muscle fibre

Fingerprint

Dive into the research topics of 'The stiffness response of type IIa fibres after eccentric exercise-induced muscle damage is dependent on ACTN3 r577X polymorphism'. Together they form a unique fingerprint.

Cite this