The effect of exercise training on transverse tubules in normal, remodeled, and reverse remodeled hearts

Ole J. Kemi*, Morten A. Hoydal, Niall Macquaide, Per M. Haram, Lauren G. Koch, Steven L. Britton, Oyvind Ellingsen, Godfrey L. Smith, Ulrik Wisloff

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

The response of transverse (T)-tubules to exercise training in health and disease remains unclear. Therefore, we studied the effect of exercise training on the density and spacing of left ventricle cardiomyocyte T-tubules in normal and remodeled hearts that associate with detubulation, by confocal laser scanning microscopy. First, exercise training in normal rats increased cardiomyocyte volume by 16% (P < 0.01), with preserved T-tubule density. Thus, the T-tubules adapted to the physiologic hypertrophy. Next, we studied T-tubules in a rat model of metabolic syndrome with pressure overload-induced concentric left ventricle hypertrophy, evidenced by 15% (P < 0.01) increased cardiomyocyte size. These rats had only 85% (P < 0.01) of the T-tubule density of control rats. Exercise training further increased cardiomyocyte volume by 8% (P < 0.01); half to that in control rats, but the T-tubule density remained unchanged. Finally, post-myocardial infarction heart failure induced severe cardiac pathology, with a 70% (P < 0.01) increased cardiomyocyte volume that included both eccentric and concentric hypertrophy and 55% (P < 0.01) reduced T-tubule density. Exercise training reversed 50% (P < 0.01) of the pathologic hypertrophy, whereas the T-tubule density increased by 40% (P < 0.05) compared to sedentary heart failure, but remained at 60% of normal hearts (P < 0.01). Physiologic hypertrophy associated with conserved T-tubule spacing (~1.8-1.9 µm), whereas in pathologic hypertrophy, T-tubules appeared disorganized without regular spacing. In conclusion, cardiomyocytes maintain the relative T-tubule density during physiologic hypertrophy and after mild concentric pathologic hypertrophy, whereas after severe pathologic remodeling with a substantial loss of T-tubules; exercise training reverses the remodeling and partly corrects the T-tubule density.

Original languageEnglish
Pages (from-to)2235-2243
Number of pages9
JournalJournal of Cellular Physiology
Volume226
Issue number9
Early online date9 Jun 2011
DOIs
Publication statusPublished - Sep 2011

Keywords

  • Animals
  • Cell Shape
  • Cell Surface Extensions/pathology
  • Fourier Analysis
  • Heart Failure/complications
  • Heart Function Tests
  • Hypertrophy, Left Ventricular/complications
  • Myocardial Infarction/complications
  • Myocardium/pathology
  • Myocytes, Cardiac/pathology
  • Oxygen Consumption
  • Physical Conditioning, Animal
  • Rats
  • Ventricular Remodeling/physiology

Fingerprint Dive into the research topics of 'The effect of exercise training on transverse tubules in normal, remodeled, and reverse remodeled hearts'. Together they form a unique fingerprint.

  • Cite this

    Kemi, O. J., Hoydal, M. A., Macquaide, N., Haram, P. M., Koch, L. G., Britton, S. L., Ellingsen, O., Smith, G. L., & Wisloff, U. (2011). The effect of exercise training on transverse tubules in normal, remodeled, and reverse remodeled hearts. Journal of Cellular Physiology, 226(9), 2235-2243. https://doi.org/10.1002/jcp.22559