Greater Oxidative Capacity in Primary Myotubes from Endurance-trained Women

Timothy D. Heden, Terence E. Ryan, Patrick J. Ferrara, Robert C. Hickner, Patricia M. Brophy, P. Darrell Neufer, Joseph M. McClung, Katsuhiko Funai

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Purpose Exercise training promotes skeletal muscle mitochondrial biogenesis and an increase in maximal oxygen consumption. Primary myotubes retain some metabolic properties observed in vivo but it is unknown whether this includes exercise-induced mitochondrial adaptations. The goal of this study was to test if primary myotubes from exercise-trained women have higher mitochondrial content and maximal oxygen consumption compared with untrained women. Methods Six trained and nine untrained white women participated in this study. Muscle biopsies from the vastus lateralis muscle of the right leg were obtained and primary muscle cells were isolated. Maximal respiration rates, mitochondrial mRNA and protein content, and succinate dehydrogenase activity were measured in skeletal muscle and primary myotubes from trained and untrained women. Results Trained women, compared with untrained women, had higher maximal whole-body oxygen consumption (+18%, P = 0.03), in vivo maximal skeletal muscle oxidative capacity measured with near infrared spectroscopy (+48%, P < 0.01), and maximal oxygen consumption in permeabilized muscle fibers (+38%, P = 0.02), which coincided with higher protein levels of muscle mitochondrial enzymes. Primary myotubes from trained women had higher maximal oxygen consumption (+38%, P = 0.03), suggesting that some elements of exercise-induced metabolic programming persists ex vivo. Consistent with this idea, myotubes from trained women had higher mRNA levels of transcriptional regulators of mitochondrial biogenesis in addition to higher protein levels of mitochondrial enzymes. Conclusions These data suggest the existence of an "exercise metabolic program," where primary myotubes isolated from exercise-trained individuals exhibit greater mitochondrial content and oxidative capacity compared with untrained individuals. These myotubes may be a useful model to study molecular mechanisms relevant to exercise adaptations in human skeletal muscle.

Original languageEnglish (US)
Pages (from-to)2151-2157
Number of pages7
JournalMedicine and science in sports and exercise
Volume49
Issue number11
DOIs
StatePublished - Nov 1 2017
Externally publishedYes

Bibliographical note

Funding Information:
This project was supported by grants NIH DK107397, DK109888, DK095774 (to K. F.), HL125695 (to J. M. M.), DK110656 (to P. D. N.), HL129632 (to T. E. R.), DK109556, DK110338, and AHA 16POST30980047 (to T. D. H.).

Publisher Copyright:
© 2017 by the American College of Sports Medicine.

Keywords

  • EXERCISE
  • HUMAN SATELLITE CELLS
  • MITOCHONDRIA
  • OXIDATIVE CAPACITY

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