Electronic supplementary material
The online version of this article (doi:10.1186/1471-2261-14-84) contains supplementary material, which is available to authorized users.
Fernando Rodrigues, Daniele Jardim Feriani contributed equally to this work.
The authors have no conflicts of interest to declare.
FR: Data acquisition, analysis and interpretation; DJF: Data acquisition, analysis, interpretation; CAB: Data acquisition and analyze; MEVA: Data acquisition and analysis; LYR: Data acquisition and analysis; NMC: Data acquisition; CM: Data analysis and interpretation; DF: Data acquisition and analyze; GIHS: Data analysis and interpretation; KDA: Statistical analysis and helped to draft the manuscript; MCI: interpretation of data and helped to draft the manuscript; BR: conception and design of the work and draft the manuscript. All authors approved final version to be published.
It has been suggested that exercise training (ET) protects against the pathological remodeling and ventricular dysfunction induced by myocardial infarction (MI). However, it remains unclear whether the positive adjustments on baroreflex and cardiac autonomic modulations promoted by ET may afford a cardioprotective mechanism. The aim of this study was to evaluate the effects of aerobic ET, prior to MI, on cardiac remodeling and function, as well as on baroreflex sensitivity and autonomic modulation in rats.
Male Wistar rats were divided into 4 groups: sedentary rats submitted to Sham surgery (C); trained rats submitted to Sham surgery (TC); sedentary rats submitted to MI (I), trained rats submitted to MI (TI). Sham and MI were performed after ET period. After surgeries, echocardiographic, hemodynamic and autonomic (baroreflex sensitivity, cardiovascular autonomic modulation) evaluations were conducted.
Prior ET prevented an additional decline in exercise capacity in TI group in comparison with I. MI area was not modified by previous ET. ET was able to increase the survival and prevent additional left ventricle dysfunction in TI rats. Although changes in hemodynamic evaluations were not observed, ET prevented the decrease of baroreflex sensitivity, and autonomic dysfunction in TI animals when compared with I animals. Importantly, cardiac improvement was associated with the prevention of cardiac autonomic impairment in studied groups.
Prior ET was effective in changing aerobic capacity, left ventricular morphology and function in rats undergoing MI. Furthermore, these cardioprotective effects were associated with attenuated cardiac autonomic dysfunction observed in trained rats. Although these cause-effect relationships can only be inferred, rather than confirmed, our study suggests that positive adaptations of autonomic function by ET can play a vital role in preventing changes associated with cardiovascular disease, particularly in relation to MI.