Treadmill exercise training prevents myocardial mechanical dysfunction induced by androgenic-anabolic steroid treatment in rats

PLoS One. 2014 Feb 12;9(2):e87106. doi: 10.1371/journal.pone.0087106. eCollection 2014.

Abstract

Elevated concentrations of testosterone and its synthetic analogs may induce changes in cardiovascular function. However, the effects of the combination of anabolic/androgenic steroid (AAS) treatment and exercise training on systolic and diastolic cardiac function are poorly understood. In the present study, we aimed to investigate the effects of low-dose steroid treatment (stanozolol) on cardiac contractile parameters when this steroid treatment was combined with exercise training in rats and the effects of chronic steroid treatment on the Frank-Starling (length-tension curves) relationship. Male Wistar rats were randomly assigned to one of four groups: U (untrained), US (untrained and treated with stanozolol 5 mg/kg/week), T (trained, 16 m/min/1 h) and TS (trained and treated with stanozolol 5 mg/kg/week). Continuous exercise training was conducted 5 days/week for 8 consecutive weeks. The speed of the treadmill was gradually increased to a final setting of 16 m/min/1 h. Experiments were divided into two independent series: 1) central hemodynamic analysis for mean arterial blood pressure (MAP) and cardiac output (CO) measurements and 2) isolated papillary muscle preparation in Krebs solution. Stanozolol treatment significantly increased the MAP and the heart size in untrained and trained rats (U 113±2; T 106±2; US 138±8 and TS 130±7 mmHg). Furthermore, stanozolol significantly decreased developed tension and dT/dt (maximal and minimal) in U rats. However, the developed tension was completely restored by training. The Frank/Starling relationship was impaired in rats treated with stanozolol; however, again, training completely restored diastolic function. Taken together, the present data suggest that AAS treatment is able to decrease cardiac performance (systolic and diastolic functions). The combination of stanozolol and physical training improved cardiac performance, including diastolic and systolic functions, independent of changes in central hemodynamic parameters. Therefore, changes in ventricular myocyte calcium transients may play a cardioprotective role.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anabolic Agents / pharmacology*
  • Animals
  • Blood Pressure
  • Cardiac Output
  • Exercise Test / methods*
  • Heart / drug effects*
  • Heart Rate / drug effects
  • Heart Ventricles / drug effects
  • Hematocrit
  • Hemodynamics / drug effects
  • Male
  • Myocardial Contraction / drug effects
  • Myocardium / pathology*
  • Organ Size / drug effects
  • Physical Conditioning, Animal
  • Rats
  • Rats, Wistar
  • Stanozolol / pharmacology*
  • Steroids / pharmacology

Substances

  • Anabolic Agents
  • Steroids
  • Stanozolol

Grant support

The authors thank FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnologico). CTB, PJT and RRC are recipients of CNPq Fellowships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.