| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Effect of exercise training and carvedilol treatment on cardiac function and structure in mice with sympathetic hyperactivity-induced heart failure
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| Autores: |
Medeiro,A.
Vanzelli,A.S.
Rosa,K.T.
Irigoyen,M.C.
Brum,P.C.
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| Data: |
2008-09-01
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| Ano: |
2008
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| Palavras-chave: |
Heart failure
Exercise training
Carvedilol treatment
Ventricular function
Cardiac remodeling
Α2A/α2CArKO mice
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| Resumo: |
The present investigation was undertaken to study the effect of β-blockers and exercise training on cardiac structure and function, respectively, as well as overall functional capacity in a genetic model of sympathetic hyperactivity-induced heart failure in mice (α2A/α2CArKO). α2A/α2CArKO and their wild-type controls were studied for 2 months, from 3 to 5 months of age. Mice were randomly assigned to control (N = 45), carvedilol-treated (N = 29) or exercise-trained (N = 33) groups. Eight weeks of carvedilol treatment (38 mg/kg per day by gavage) or exercise training (swimming sessions of 60 min, 5 days/week) were performed. Exercise capacity was estimated using a graded treadmill protocol and HR was measured by tail cuff. Fractional shortening was evaluated by echocardiography. Cardiac structure and gastrocnemius capillary density were evaluated by light microscopy. At 3 months of age, no significant difference in fractional shortening or exercise capacity was observed between wild-type and α2A/α2CArKO mice. At 5 months of age, all α2A/α2CArKO mice displayed exercise intolerance and baseline tachycardia associated with reduced fractional shortening and gastrocnemius capillary rarefaction. In addition, α2A/ α2CArKO mice presented cardiac myocyte hypertrophy and ventricular fibrosis. Exercise training and carvedilol similarly improved fractional shortening in α2A/α2CArKO mice. The effect of exercise training was mainly associated with improved exercise tolerance and increased gastrocnemius capillary density while β-blocker therapy reduced cardiac myocyte dimension and ventricular collagen to wild-type control levels. Taken together, these data provide direct evidence for the respective beneficial effects of exercise training and carvedilol in α2A/α2CArKO mice preventing cardiac dysfunction. The different mechanisms associated with beneficial effects of exercise training and carvedilol suggest future studies associating both therapies.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000900012
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X2008000900012
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.41 n.9 2008
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| Direitos: |
info:eu-repo/semantics/openAccess
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