TY - JOUR
T1 - The stiffness response of type IIa fibres after eccentric exercise-induced muscle damage is dependent on ACTN3 r577X polymorphism
AU - Broos, Siacia
AU - Malisoux, Laurent
AU - Theisen, Daniel
AU - Van Thienen, Ruud
AU - Francaux, Marc
AU - Thomis, Martine A.
AU - Deldicque, Louise
N1 - Funding Information:
The present study was funded by a grant of Research Foundation-Flanders (KAN20101.5.100.10).
Funding Information:
The present study was funded by a grant of Research Foundation-Flanders (KAN20101.5.100.10). All experiments were performed in the Exercise Physiology Research Center at the KU Leuven, except the single fibres analyses, which were performed in the Institute of Neuroscience at the Universit? catholique de Louvain. All authors participated to the conception and design of the work. SB, LM and LD acquired the data. All authors participated to the interpretation of the data and revised the draft of the manuscript. All authors approved the final version of the manuscript and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All persons designated as authors qualify for authorship, and all those who qualify for authorship are listed.
Publisher Copyright:
© 2018, © 2018 European College of Sport Science.
PY - 2019/4/21
Y1 - 2019/4/21
N2 - 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.
AB - 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.
KW - Actinin-3
KW - human skeletal muscle
KW - isolated muscle fibre
UR - http://www.scopus.com/inward/record.url?scp=85055500620&partnerID=8YFLogxK
U2 - 10.1080/17461391.2018.1529200
DO - 10.1080/17461391.2018.1529200
M3 - Article
C2 - 30360698
AN - SCOPUS:85055500620
SN - 1746-1391
VL - 19
SP - 480
EP - 489
JO - European Journal of Sport Science
JF - European Journal of Sport Science
IS - 4
ER -