Swimming exercise reverses aging-related contractile abnormalities of female heart by improving structural alterations.
Cardiol J
; 24(1): 85-93, 2017.
Article
em En
| MEDLINE
| ID: mdl-27665854
ABSTRACT
BACKGROUND:
The objective of this study was to examine the effect of swimming exercise on aging-related Ca2+ handling alterations and structural abnormalities of female rat heart.METHODS:
For this purpose, 4-month and 24-month old female rats were used and divided into three following groups sedentary young (SY), sedentary old (SO), and exercised old (Ex-O). Swimming exercise was performed for 8 weeks (60 min/day, 5 days/week). Myocyte shortening, L-type Ca2+ currents and associated Ca2+ transients were measured from ventricular myocytes at 36 ± 1°C. NOX-4 levels, aconitase activity, glutathione measurements and ultrastructural examination by electron microscopy were conducted in heart tissue.RESULTS:
Swimming exercise reversed the reduced shortening and slowed kinetics of aged cardiomyocytes. Although the current density was similar for all groups, Ca2+ transients were higher in SO and Ex-O myocytes with respect to the SY group. Caffeine-induced Ca2+ transients and the integrated NCX current were lower in cardiomyocytes of SY rats compared with other groups, suggesting an increased sarcoplasmic reticulum Ca2+ content in an aged heart. Aging led to upregulated cardiac NOX-4 along with declined aconitase activity. Although it did not reverse these oxidative parameters, swimming exercise achieved a significant increase in glutathione levels and improved structural alterations of old rats' hearts.CONCLUSIONS:
We conclude that swimming exercise upregulates antioxidant defense capacity and improves structural abnormalities of senescent female rat heart, although it does not change Ca2+ handling alterations further. Thereby, it improves contractile function of aged myocardium by mitigating detrimental effects of oxidative stress.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Natação
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Envelhecimento
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Estresse Oxidativo
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Miócitos Cardíacos
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Esforço Físico
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Contração Miocárdica
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article