The Effect of Eight Weeks of Resistance Training on Activin Receptor type II-B and Plasma Levels of Growth Differentiation Factor 11 and 8 in Cardiac Physiological Hypertrophy in Male Wistar Rats

  Exercise training can be effective on cardiac physiological hypertrophy (that is favorable for cardiac function) by changing the concentration of growth factors and their receptors. The aim of this study was to determine the effects of eight weeks of resistance training on activin receptor type II-B (ActRIIβ), as well as plasma levels of growth differentiation factor 11 (GDF11) and growth differentiation factor 8 (GDF8) in cardiac physiological hypertrophy in male Wistar rats. After the familiarization period, fourteen 3-month-old male Wistar rats were randomly divided into control and training groups (n= 7). Resistance training included 8 weeks and 5 sessions per week climbing from a 1-meter ladder. GDF11 and GDF8 of plasma were measured using enzyme-linked immunosorbent assay (ELISA) method, and ActRIIB of left ventricular myocardium was measured using immunohistochemistry (IHC) method. Data were analyzed using independent t test and Mann-Whitney U at the significance level of P < 0.050. Findings: There was a significant difference between the training and control groups in heart weight (P = 0.004), heart weight/body weight (P =0.045), GDF11 (P = 0.001), and GDF8/GDF11 (P = 0.015). There was not any significant differences between the training and control groups in ActRIIβ (P = 0.768) and GDF8 (P = 0.295) levels. According to the results of the present study, it seems that resistance training with favorable effects on growth factors is an important strategy in cardiac physiological hypertrophy.