Exercise Training Reduces Sympathetic Modulation on Cardiovascular System and Cardiac Oxidative Stress in Spontaneously Hypertensive Rats

Exercise Training Reduces Sympathetic Modulation on Cardiovascular System and Cardiac Oxidative Stress in Spontaneously Hypertensive Rats

Author Bertagnolli, Marianne Google Scholar
Schenkel, Paulo C. Google Scholar
Campos, Cristina Google Scholar
Mostarda, Cristiano T. Google Scholar
Casarini, Dulce E. Autor UNIFESP Google Scholar
Bello-Klein, Adriane Google Scholar
Irigoyen, Maria C. Autor UNIFESP Google Scholar
Rigatto, Katya Google Scholar
Institution Fed Univ Hlth Sci Porto Alegre
Univ Fed Rio Grande do Sul
Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Abstract BACKGROUNDSpontaneously hypertensive rats (SHRs) show increased cardiac sympathetic activity, which could stimulate cardiomyocyte hypertrophy, cardiac damage, and apoptosis. Norepinephrine (NE)induced cardiac oxidative stress seems to be involved in SHR cardiac hypertrophy development. Because exercise training (ET) decreases sympathetic activation and oxidative stress, it may alter cardiac hypertrophy in SHR. the aim of this study was to determine, in vivo, whether ET alters cardiac sympathetic modulation on cardiovascular system and whether a correlation exists between cardiac oxidative stress and hypertrophy.METHODSMale SHRs (15-weeks old) were divided into sedentary hypertensive (SHR, n = 7) and exercise-trained hypertensive rats (SHR-T, n = 7). Moderate ET was performed on a treadmill (5 days/week, 60 min, 10 weeks). After ET, cardiopulmonary reflex responses were assessed by bolus injections of 5-HT. Autoregressive spectral estimation was performed for systolic arterial pressure (SAP) with oscillatory components quantified as low (LF: 0.2-0.75 Hz) and high (HF:0.75-4.0 Hz) frequency ranges. Cardiac NE concentration, lipid peroxidation, antioxidant enzymes activities, and total nitrates/nitrites were determined.RESULTSET reduced mean arterial pressure, SAP variability (SAP var), LIF of SAP, and cardiac hypertrophy and increased cardiopulmonary reflex responses. Cardiac lipid peroxidation was decreased in trained SHRs and positively correlated with NE concentrations (r= 0.89, P < 0.01) and heart weight/body weight ratio (r= 0.72, P < 0.01), and inversely correlated with total nitrates/nitrites (r= -0.79, P < 0.01). Moreover, in trained SHR, cardiac total nitrates/nitrites were inversely correlated with NE concentrations (r= -0.82, P < 0.01).CONCLUSIONSET attenuates cardiac sympathetic modulation and cardiac hypertrophy, which were associated with reduced oxidative stress and increased nitric oxide (NO) bioavailability. Am J Hypertens 2008;21:1138-1193 (C) 2008 American Journal of Hypertension, Ltd.
Language English
Sponsor Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Financiadora de Estudos e Projetos (FINEP)
Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS)
Date 2008-11-01
Published in American Journal of Hypertension. New York: Nature Publishing Group, v. 21, n. 11, p. 1188-1193, 2008.
ISSN 0895-7061 (Sherpa/Romeo, impact factor)
Publisher Nature Publishing Group
Extent 1188-1193
Origin http://dx.doi.org/10.1038/ajh.2008.270
Access rights Closed access
Type Article
Web of Science ID WOS:000260312100007
URI http://repositorio.unifesp.br/handle/11600/31017

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