Effects of Growth Hormone on Cardiac Remodeling During Resistance Training in Rats

Abstract Background: Although the beneficial effects of resistance training (RT) on the cardiovascular system are well established, few studies have investigated the effects of the chronic growth hormone (GH) administration on cardiac remodeling during an RT program. Objective: To evaluate the effects of GH on the morphological features of cardiac remodeling and Ca2+ transport gene expression in rats submitted to RT. Methods: Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH, RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30 days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3 bouts/wk) for 30 consecutive days. After the experimental period, the following variables were analyzed: final body weight (FBW), left ventricular weight (LVW), LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction, creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a, phospholamban (PLB) and ryanodine (RyR). Results: There was no significant (p > 0.05) difference among groups for FBW, LVW, LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The RT group showed a significant (p < 0.05) increase in collagen fraction compared to the other groups. Additionally, the trained groups (RT and RTGH) had greater CK-MB levels compared to the untrained groups (CT and GH). Conclusion: GH may attenuate the negative effects of RT on cardiac remodeling by counteracting the increased collagen synthesis, without affecting the gene expression that regulates cardiac Ca2+ transport

Treinamento isodinâmico em UBS melhora qualidade de vida e capacidade funcional de mulheres

Objective: To evaluate and compare the effects of isodynamic training on func - tional capacity and quality of life of women with cardiovascular risk factors registered at Basic Health Unit (BHU). Methods: The study included 26 women divided into two groups: a control group (n=13) of women who did not exercise regularly, and a training group (n=13), whose members performed isodynamic training (walking exercise associated with upper limb exercise performed in di - agonals with 1 kg weight and elastic tubing) in a frequency of three sessions / week for an hour each. Results: Women in the training group had better func - tional capacity and an improved quality of life compared with the participants in the control group. Conclusion: The isodynamic training proved to be a simple, low-cost measure for health prevention and protection in suburban areas