Document Detail


Exercise training reduces sympathetic modulation on cardiovascular system and cardiac oxidative stress in spontaneously hypertensive rats.
MedLine Citation:
PMID:  18787517     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Spontaneously 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.
METHODS: Male 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.
RESULTS: ET reduced mean arterial pressure, SAP variability (SAP var), LF 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).
CONCLUSIONS: ET attenuates cardiac sympathetic modulation and cardiac hypertrophy, which were associated with reduced oxidative stress and increased nitric oxide (NO) bioavailability.
Authors:
Mariane Bertagnolli; Paulo C Schenkel; Cristina Campos; Cristiano T Mostarda; Dulce E Casarini; Adriane Belló-Klein; Maria C Irigoyen; Katya Rigatto
Related Documents :
8542527 - Oxygen uptake and cardiac output during progressive and constant load work in patients ...
9269617 - Near continuous cardiac output by thermodilution.
20848127 - Cardiac output but not stroke volume is similar in a wingate and vo2peak test in young ...
11087257 - Effects of exercise training on cardiac function, gene expression, and apoptosis in rats.
901377 - Myocardial blood flow distribution in miniature pigs during exercise.
15358607 - Biphasic temporal pattern in exercise capacity after myocardial infarction in the rat: ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-09-11
Journal Detail:
Title:  American journal of hypertension     Volume:  21     ISSN:  1941-7225     ISO Abbreviation:  Am. J. Hypertens.     Publication Date:  2008 Nov 
Date Detail:
Created Date:  2008-10-22     Completed Date:  2009-01-30     Revised Date:  2011-06-30    
Medline Journal Info:
Nlm Unique ID:  8803676     Medline TA:  Am J Hypertens     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1188-93     Citation Subset:  IM    
Affiliation:
Laboratory of Cardiovascular Physiology, Department of Physiology, Basic and Health Science Institute, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / physiology
Cardiovascular Physiological Phenomena
Cardiovascular System / innervation*
Heart / physiology*
Heart Ventricles / pathology
Hypertension / physiopathology*,  prevention & control*
Hypertrophy / physiopathology,  prevention & control
Lipid Peroxidation / physiology
Male
Nitric Oxide / metabolism
Norepinephrine / metabolism
Oxidative Stress / physiology*
Physical Conditioning, Animal / physiology*
Rats
Rats, Inbred SHR
Sympathetic Nervous System / physiology*
Chemical
Reg. No./Substance:
10102-43-9/Nitric Oxide; 51-41-2/Norepinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  The effects of a 6-month sodium restriction on cardiac autonomic function in patients with mild to m...
Next Document:  Arterial properties in relation to genetic variations in the adducin subunits in a white population.