HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 104/1/103    most recent 00493.2007v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Medeiros, A. Articles by Brum, P. C. Search for Related Content PubMed PubMed Citation Articles by Medeiros, A. Articles by Brum, P. C.

Exercise training delays cardiac dysfunction and prevents calcium handling abnormalities in sympathetic hyperactivity-induced heart failure mice

¹School of Physical Education and Sport, University of São Paulo; ²Heart Institute (InCor), School of Medicine, University of São Paulo; and ³Department of Medicine, Division of Nephrology, Federal University of São Paulo, São Paulo, Brazil

Submitted 7 May 2007 ; accepted in final form 30 October 2007

Exercise training (ET) is a coadjuvant therapy in preventive cardiology. It delays cardiac dysfunction and exercise intolerance in heart failure (HF); however, the molecular mechanisms underlying its cardioprotection are poorly understood. We tested the hypothesis that ET would prevent Ca²⁺ handling abnormalities and ventricular dysfunction in sympathetic hyperactivity-induced HF mice. A cohort of male wild-type (WT) and congenic _2A/_2C-adrenoceptor knockout (_2A/_2CARKO) mice with C57BL6/J genetic background (3–5 mo of age) were randomly assigned into untrained and exercise-trained groups. ET consisted of 8-wk swimming session, 60 min, 5 days/wk. Fractional shortening (FS) was assessed by two-dimensional guided M-mode echocardiography. The protein expression of ryanodine receptor (RyR), phospho-Ser²⁸⁰⁹-RyR, sarcoplasmic reticulum Ca²⁺ ATPase (SERCA2), Na⁺/Ca²⁺ exchanger (NCX), phospholamban (PLN), phospho-Ser¹⁶-PLN, and phospho-Thr¹⁷-PLN were analyzed by Western blotting. At 3 mo of age, no significant difference in FS and exercise tolerance was observed between WT and _2A/_2CARKO mice. At 5 mo, when cardiac dysfunction is associated with lung edema and increased plasma norepinephrine levels, _2A/_2CARKO mice presented reduced FS paralleled by decreased SERCA2 (26%) and NCX (34%). Conversely, _2A/_2CARKO mice displayed increased phospho-Ser¹⁶-PLN (76%) and phospho-Ser²⁸⁰⁹-RyR (49%). ET in _2A/_2CARKO mice prevented exercise intolerance, ventricular dysfunction, and decreased plasma norepinephrine. ET significantly increased the expression of SERCA2 (58%) and phospho-Ser¹⁶-PLN (30%) while it restored the expression of phospho-Ser²⁸⁰⁹-RyR to WT levels. Collectively, we provide evidence that improved net balance of Ca²⁺ handling proteins paralleled by a decreased sympathetic activity on ET are, at least in part, compensatory mechanisms against deteriorating ventricular function in HF.

calcium handling proteins; ventricular function; plasma norepinephrine levels; cardiomyopathy; exercise conditioning

This article has been cited by other articles:

				T. Bupha-Intr, J. Laosiripisan, and J. Wattanapermpool Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats J Appl Physiol, October 1, 2009; 107(4): 1105 - 1112. [Abstract] [Full Text] [PDF]

				D. Lachance, E. Plante, A.-A. Bouchard-Thomassin, S. Champetier, E. Roussel, M.-C. Drolet, M. Arsenault, and J. Couet Moderate Exercise Training Improves Survival and Ventricular Remodeling in an Animal Model of Left Ventricular Volume Overload Circ Heart Fail, September 1, 2009; 2(5): 437 - 445. [Abstract] [Full Text] [PDF]

				R. S. F. Oliveira, J. C. B. Ferreira, E. R. M. Gomes, N. A. Paixão, N. P. L. Rolim, A. Medeiros, S. Guatimosim, and P. C. Brum Cardiac anti-remodelling effect of aerobic training is associated with a reduction in the calcineurin/NFAT signalling pathway in heart failure mice J. Physiol., August 1, 2009; 587(15): 3899 - 3910. [Abstract] [Full Text] [PDF]

				A. V. N. Bacurau, M. A. Jardim, J. C. B. Ferreira, L. R. G. Bechara, C. R. Bueno Jr., T. C. Alba-Loureiro, C. E. Negrao, D. E. Casarini, R. Curi, P. R. Ramires, et al. Sympathetic hyperactivity differentially affects skeletal muscle mass in developing heart failure: role of exercise training J Appl Physiol, May 1, 2009; 106(5): 1631 - 1640. [Abstract] [Full Text] [PDF]

				C. D. Garciarena, O. A. Pinilla, M. B. Nolly, R. P. Laguens, E. M. Escudero, H. E. Cingolani, and I. L. Ennis Endurance Training in the Spontaneously Hypertensive Rat: Conversion of Pathological into Physiological Cardiac Hypertrophy Hypertension, April 1, 2009; 53(4): 708 - 714. [Abstract] [Full Text] [PDF]