Moderate-Intensity Swimming Alleviates Oxidative Injury in Ischemic Heart

The global burden of cardiovascular diseases is indisputable, as it claims nearly 18 million lives a year. In this current study, we aimed to prove that exercise, a cornerstone in cardiovascular disease management, emerges as a powerful tool in the pathology of myocardial ischemia. Male rats were divided into three groups: pre-swimming training + isoproterenol (ISO) treated, isoproterenol-treated, and control-sedentary. Myocardial infarction was induced by the subcutaneous injection of 1.0 mg/kg ISO. After the subsequent rest period, the animals swam for 3 weeks, every day for 25 min. At the end of the experiment, the serum levels of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), as well as the cardiac concentrations of reactive oxygen species (ROS), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were determined. Our results indicate that both cardiac injury biomarkers (ANP, BNP) and ROS levels were significantly lower in swimming rats compared to the sedentary animals. Moreover, the level of enzymatic components of the intracellular antioxidant system, CAT, SOD, and GPx were increased in swimming animals after ISO-induced myocardial infarction. Our findings support the fact that moderate-intensity swimming training can be efficiently used to prevent myocardial infarction-induced ischemic injury, by inhibiting ROS production and strengthening intracellular antioxidant defense.