Int J Sports Med
DOI: 10.1055/a-1300-2583
Physiology & Biochemistry

Digoxin Combined with Aerobic Interval Training Improved Cardiomyocyte Contractility

Gabriel Vasconcelos Abreu
1  Laboratory of Metabolic and Cardiovascular Diseases, Health Education and Research Center (NUPADS), Institute of Health Science, Federal University of Mato Grosso, Sinop, Brazil
,
Erick Roberto Gonçalves Claudio
2  Center of Physical Education and Sports, Department of Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
,
Andreo Fernando Aguiar
3  North University of Paraná (UNOPAR), Centre of Research in Biological and Healthy Sciences, Londrina, Paraná, Brazil
,
Morenna Alana Giordani
1  Laboratory of Metabolic and Cardiovascular Diseases, Health Education and Research Center (NUPADS), Institute of Health Science, Federal University of Mato Grosso, Sinop, Brazil
,
Eveline Aparecida Isquierdo Fonseca de Queiroz
1  Laboratory of Metabolic and Cardiovascular Diseases, Health Education and Research Center (NUPADS), Institute of Health Science, Federal University of Mato Grosso, Sinop, Brazil
,
Ana Paula Lima-Leopoldo
2  Center of Physical Education and Sports, Department of Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
,
2  Center of Physical Education and Sports, Department of Sports, Federal University of Espírito Santo, Vitória, Espírito Santo, Brazil
,
Mário Mateus Sugizaki
1  Laboratory of Metabolic and Cardiovascular Diseases, Health Education and Research Center (NUPADS), Institute of Health Science, Federal University of Mato Grosso, Sinop, Brazil
› Author Affiliations
Funding: This work was supported by Mato Grosso State Research Support Foundation (Fapemat), process 470627/2011

Abstract

Digoxin is a cardiotonic that increases the cardiac output without causing deleterious effects on heart, as well as improves the left ventricular performance during physical exercise. We tested whether the association between chronic digoxin administration and aerobic interval training (AIT) promotes beneficial cardiovascular adaptations by improving the myocardial contractility and calcium (Ca2+) handling. Male Wistar rats were randomly assigned to sedentary control (C), interval training (T), sedentary digoxin (DIGO) and T associated to digoxin (TDIGO). AIT was performed on a treadmill (1h/day, 5 days/week) for 60 days, consisting of successive 8-min periods at 80% and 20% of VO2máx for 2 min. Digoxin was administered by orogastric gavage for 60 days. Left ventricle samples were collected to analysis of Ca2+ handling proteins; contractility and Ca2+ handling were performed on isolated cardiomyocytes. TDIGO group had a greater elevation in fractional shortening (44%) than DIGO, suggesting a cardiomyocyte contractile improvement. In addition, T or TDIGO groups showed no change in cardiomyocytes properties after Fura2-acetoxymethyl ester, as well as in sarcoplasmic reticulum Ca2+-ATPase (SERCA2a), phospholamban and calcineurin expressions. The main findings indicate that association of digoxin and aerobic interval training improved the cardiomyocyte contractile function, but these effects seem to be unrelated to Ca2+ handling.



Publication History

Received: 30 May 2020

Accepted: 16 October 2020

Publication Date:
15 December 2020 (online)

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