|
|
||||||||
1James Hogg/iCAPTUR4E Centre for Cardiovascular and Pulmonary Research, Department of Pathology and Laboratory Medicine, University of British Columbia-St. Paul's Hospital, Vancouver, British Columbia V6Z 1Y6; 2Division of Sports Medicine, Departments of Zoology and Radiology, the University of British Columbia, Vancouver, British Columbia V6T 1Z4; 3Department of Human Biology and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1; 4Faculté des Sciences, Université de Paris XII, Creteil Cedex 94010, France; 5Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, Illinois 62794; and 6Department of Biochemistry and Molecular Genetics, University of Alabama, Birmingham, Alabama 35294
Submitted 1 October 2003 ; accepted in final form 14 April 2004
Adaptation of myocardial energy substrate utilization may contribute to the cardioprotective effects of regular exercise, a possibility supported by evidence showing that pharmacological metabolic modulation is beneficial to ischemic hearts during reperfusion. Thus we tested the hypothesis that the beneficial effect of regular physical exercise on recovery from ischemia-reperfusion is associated with a protective metabolic phenotype. Function, glycolysis, and oxidation of glucose, lactate, and palmitate were measured in isolated working hearts from sedentary control (C) and treadmill-trained (T: 10 wk, 4 days/wk) female Sprague-Dawley rats submitted to 20 min ischemia and 40 min reperfusion. Training resulted in myocardial hypertrophy (1.65 ± 0.05 vs. 1.30 ± 0.03 g heart wet wt, P < 0.001) and improved recovery of function after ischemia by nearly 50% (P < 0.05). Glycolysis was 2530% lower in T hearts before and after ischemia (P < 0.05), whereas rates of glucose oxidation were 45% higher before ischemia (P < 0.01). As a result, the fraction of glucose oxidized before and after ischemia was, respectively, twofold and 25% greater in T hearts (P < 0.05). Palmitate oxidation was 5065% greater in T than in C before and after ischemia (P < 0.05), whereas lactate oxidation did not differ between groups. Alteration in content of selected enzymes and proteins, as assessed by immunoblot analysis, could not account for the reduction in glycolysis or increase in glucose and palmitate oxidation observed. Combined with the studies on the beneficial effect of pharmacological modulation of energy metabolism, the present results provide support for a role of metabolic adaptations in protecting the trained heart against ischemia-reperfusion injury.
exercise training; cardiac hypertrophy; ischemia-reperfusion; energy metabolism
This article has been cited by other articles:
![]() |
S. Boudina, S. Sena, H. Theobald, X. Sheng, J. J. Wright, X. X. Hu, S. Aziz, J. I. Johnson, H. Bugger, V. G. Zaha, et al. Mitochondrial Energetics in the Heart in Obesity-Related Diabetes: Direct Evidence for Increased Uncoupled Respiration and Activation of Uncoupling Proteins Diabetes, October 1, 2007; 56(10): 2457 - 2466. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. S. Laaksonen, K. K. Kalliokoski, M. Luotolahti, J. Kemppainen, M. Teras, H. Kyrolainen, P. Nuutila, and J. Knuuti Myocardial perfusion during exercise in endurance-trained and untrained humans Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2007; 293(2): R837 - R843. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. W. Starnes, B. D. Barnes, and M. E. Olsen Exercise training decreases rat heart mitochondria free radical generation but does not prevent Ca2+-induced dysfunction J Appl Physiol, May 1, 2007; 102(5): 1793 - 1798. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Marcil, K. Bourduas, A. Ascah, and Y. Burelle Exercise training induces respiratory substrate-specific decrease in Ca2+-induced permeability transition pore opening in heart mitochondria Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1549 - H1557. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. R. Libonati, Z. V. Kendrick, and S. R. Houser Sprint training improves postischemic, left ventricular diastolic performance J Appl Physiol, December 1, 2005; 99(6): 2121 - 2127. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Hagg, B. Wandt, G. Bergstrom, R. Volkmann, and L.-m. Gan Physical exercise capacity is associated with coronary and peripheral vascular function in healthy young adults Am J Physiol Heart Circ Physiol, October 1, 2005; 289(4): H1627 - H1634. [Abstract] [Full Text] [PDF] |
||||
![]() |
U. Hagg, M. E. Johansson, J. Gronros, A. S. Naylor, I. H. Jonsdottir, G. Bergstrom, P.-A. Svensson, and L.-m. Gan Gene expression profile and aortic vessel distensibility in voluntarily exercised spontaneously hypertensive rats: potential role of heat shock proteins Physiol Genomics, August 11, 2005; 22(3): 319 - 326. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Chicco, C. M. Schneider, and R. Hayward Voluntary exercise protects against acute doxorubicin cardiotoxicity in the isolated perfused rat heart Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R424 - R431. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Saeedi, M. Grist, R. B. Wambolt, A. Bescond-Jacquet, A. Lucien, and M. F. Allard Trimetazidine Normalizes Postischemic Function of Hypertrophied Rat Hearts J. Pharmacol. Exp. Ther., July 1, 2005; 314(1): 446 - 454. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Kloner and B. Z. Simkhovich Benefit of an exercise program before myocardial infarction J. Am. Coll. Cardiol., March 15, 2005; 45(6): 939 - 940. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |