Digoxin Combined with Aerobic Interval Training Improved Cardiomyocyte Contractility

Area of Science:

• Cardiovascular Physiology
• Exercise Science
• Pharmacology

Background:

• Digoxin, a cardiotonic drug, improves cardiac output and left ventricular function during exercise.
• Aerobic interval training (AIT) is known to induce beneficial cardiovascular adaptations.
• The combined effects of digoxin and AIT on myocardial contractility and calcium handling remain underexplored.

Purpose of the Study:

• To investigate whether chronic digoxin administration combined with AIT promotes beneficial cardiovascular adaptations.
• To assess the impact on myocardial contractility and intracellular calcium (Ca2+) handling.

Main Methods:

• Male Wistar rats were divided into four groups: control, AIT, digoxin, and AIT + digoxin.
• AIT involved treadmill exercise for 60 days.
• Digoxin was administered orally for 60 days.
• Cardiomyocyte contractility and Ca2+ handling were analyzed, along with key protein expressions.

Main Results:

• The AIT + digoxin group showed a significant increase in fractional shortening compared to the digoxin-only group, indicating improved cardiomyocyte contractility.
• No significant changes were observed in cardiomyocyte properties or the expression of key Ca2+ handling proteins (SERCA2a, phospholamban, calcineurin) in response to AIT or the combined treatment.

Conclusions:

• The combination of digoxin and AIT enhances cardiomyocyte contractile function.
• These improvements in cardiac contractility appear to be independent of alterations in myocardial calcium handling mechanisms.