Regulation of oxidative enzyme activity and eukaryotic elongation factor 2 in human skeletal muscle: influence of gender and exercise

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Carsten Roepstorff
  • P. Schjerling
  • Bodil Vistisen
  • M. Madsen
  • C.H. Steffensen
  • M.H. Rider
  • Kiens, Bente

AIM: To investigate gender-related differences in the responses of oxidative enzymes and eukaryotic elongation factor-2 (eEF2) to exercise. METHODS: The influence of exercise (90 min, 60%VO(2peak)) on citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (HAD) activity and mRNA content, together with eEF2 expression and phosphorylation at rest, were assessed in skeletal muscle of untrained (UT) and endurance trained (ET) females and males. RESULTS: Citrate synthase and HAD mRNA were higher in females than in males (27% and 48%, respectively, P < 0.05) whereas CS and HAD activity did not differ between females and males (NS). In females only, CS activity was enhanced (P < 0.05) by 90 min exercise. Resting CS mRNA content did not differ between UT and ET but, nevertheless, CS activity was 56% higher in ET than in UT volunteers (P < 0.001). HAD mRNA and activity were not influenced by training status (NS). In UT, CS mRNA was enhanced 37% (P < 0.05) by exercise whereas exercise did not change CS mRNA in ET (NS). eEF2 expression was 31% higher (P < 0.05) and eEF2 Thr56 phosphorylation (which leads to translation inhibition) was 24% lower (P < 0.05) in females than in males. eEF2 expression and phosphorylation were unaffected by training status (NS). CONCLUSION: Basal transcriptional, translational, and/or post-translational control of CS and HAD seems to be gender-dependent. Also, gender differences in translation and/or post-translational protein modification of CS occur during exercise. Accordingly, the potential for peptide-chain elongation, based on eEF2 expression and phosphorylation, appears to be higher in females than in males.

OriginalsprogEngelsk
TidsskriftActa Physiologica (Print Edition)
Vol/bind184
Udgave nummer3
Sider (fra-til)215-224
ISSN1748-1708
StatusUdgivet - 2005

Bibliografisk note

PUF 2005 5200 005

ID: 92726