miun.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Strength, power, fiber types, and mRNA expression in trained men and women with different ACTN3 R577X genotypes
Show others and affiliations
2009 (English)In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 106, p. 959-965Article in journal (Refereed) Published
Abstract [en]

.-alpha-Actinins are structural proteins of the Z-line. Human skeletal muscle expresses two alpha-actinin isoforms, alpha-actinin-2 and alpha-actinin-3, encoded by their respective genes ACTN2 and ACTN3. ACTN2 is expressed in all muscle fiber types, while only type II fibers, and particularly the type IIb fibers, express ACTN3. ACTN3 (R577X) polymorphism results in loss of alpha-actinin-3 and has been suggested to influence skeletal muscle function. The X allele is less common in elite sprint and power athletes than in the general population and has been suggested to be detrimental for performance requiring high power. The present study investigated the association of ACTN3 genotype with muscle power during 30-s Wingate cycling in 120 moderately to well-trained men and women and with knee extensor strength and fatigability in a subset of 21 men performing isokinetic exercise. Muscle biopsies were obtained from the vastus lateralis muscle to determine fiber-type composition and ACTN2 and ACTN3 mRNA levels. Peak and mean power and the torque-velocity relationship and fatigability output showed no difference across ACTN3 genotypes. Thus this study suggests that R577X polymorphism in ACTN3 is not associated with differences in power output, fatigability, or force-velocity characteristics in moderately trained individuals. However, repeated exercise bouts prompted an increase in peak torque in RR but not in XX genotypes, suggesting that ACTN3 genotype may modulate responsiveness to training. Our data further suggest that alpha-actinins do not play a significant role in determining muscle fiber-type composition. Finally, we show that ACTN2 expression is affected by the content of alpha-actinin-3, which implies that alpha-actinin-2 may compensate for the lack of alpha-actinin-3 and hence counteract the phenotypic consequences of the deficiency.

Place, publisher, year, edition, pages
2009. Vol. 106, p. 959-965
National Category
Sport and Fitness Sciences
Identifiers
URN: urn:nbn:se:miun:diva-8787DOI: 10.1152/japplphysiol.91435.2008ISI: 000263719700029Scopus ID: 2-s2.0-64349112961OAI: oai:DiVA.org:miun-8787DiVA, id: diva2:211497
Available from: 2009-04-15 Created: 2009-04-15 Last updated: 2017-12-13Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Tesch, Per A

Search in DiVA

By author/editor
Tesch, Per A
By organisation
Department of Health Sciences
In the same journal
Journal of applied physiology
Sport and Fitness Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 54 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf