Influence of resistance exercise on cardiac remodeling and soleus muscle of infarcted rats Academic Article uri icon

abstract

  • Abstract Introduction Resistance exercise (RE) provides several benefits for healthy individuals. However, its effects during heart failure are unclear. The aim of this study was to evaluate the effects of RE on functional capacity, cardiac remodeling, and soleus muscle molecular and biochemical features in rats with myocardial infarction (MI). Methods Three months after MI or simulated surgery (Sham), Wistar rats were divided into three groups: Sham (n=14), MI (n=13), and MI subjected to RE (RE-MI, n=14). Exercised rats trained 3 times a week performing four climbs with progressive loads on a ladder over 12 weeks. Functional capacity was assessed by maximum carrying capacity test in the ladder and exercise tolerance test in treadmill. Echocardiogram was performed at the end of the study. Energy metabolism and antioxidant enzyme activities were assessed by spectrophotometry in the soleus muscle. Oxidative stress markers were analyzed in soleus muscle (lipid hydroperoxide) or serum (malondialdehyde and protein carbonylation). Protein expression of insulin type-1 growth factor-like pathway, protein kinase B, and rapamycin target complex was analyzed by Western-blot. Statistical analysis: ANOVA and Bonferroni or Dunn, Student's t and Goodman tests; p>0.05. Results Mortality was higher in MI than Sham. Infarction size did not differ between groups. Resistance exercise increased maximum load carrying capacity, without changing functional capacity or cardiac remodeling. Catalase activity was lower in MI than Sham and glutathione peroxidase activity was lower in MI than Sham and RE-MI. Protein carbonylation was higher in RE-MI than MI. Energy metabolism did not differ between groups, except for lower phosphofructokinase activity in RE-MI than MI. Expression of p70s6K, p-FoxO3a, and p-FoxO3a-to-FoxO3a ratio was lower, and p-p70s6K-to-p70s6K ratio was higher in MI than Sham. Conclusion The practice of resistance exercise is safe, attenuates mortality, and improves maximum load carrying capacity regardless of changes in cardiac remodeling in infarcted rats. In soleus muscle, resistance exercise preserves phosphofructokinase and antioxidant enzyme activity and expression of the proteins involved in muscle trophism. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): CNPq UNESP

published proceedings

  • European Heart Journal

author list (cited authors)

  • Souza, L. M., Gomes, M. J., Pagan, L. U., Rodrigues, E. A., Pontes, T., Fernandes, A., ... Okoshi, M. P.

citation count

  • 0

complete list of authors

  • Souza, LM||Gomes, MJ||Pagan, LU||Rodrigues, EA||Pontes, THD||Fernandes, AAH||Murata, GM||Zornoff, LAM||Okoshi, K||Okoshi, MP

publication date

  • October 2021