Low-intensity exercise improves cardiac tolerance to ischemia/reperfusion injury in aged female rats with metabolic syndrome

Abstract

Metabolic syndrome (MetS) is a group of cardiovascular risk factors which has higher prevalence in the elderly population. Being an aged obese woman with raised arterial blood pressure and blood glucose level might increase the risk of having cardiovascular morbidity or mortality during an attack of myocardial infarction. The present study was designed to evaluate the cardioprotective efficacy of a low intensity swim-exercise program on ischemic reperfusion injury in isolated perfused hearts from aged female rats with MetS. Wistar rats were allocated into three groups: controls, MetS-sedentary, and MetS-exercised. Body weight (BW) and waist circumference were measured with calculation of body mass index (BMI). Blood pressure, fasting blood glucose (FBG) and lipid profile were determined. Cardiac activities of isolated hearts were studied on Langendorff preparation under basal conditions and following ischemia/reperfusion (I/R), and the level of cardiac tissue nitrite was also assessed. MetS-exercised rats showed restoration of control values for BW, BMI, waist circumference, visceral fat, FBG, plasma lipid profile and left ventricular nitrite content. Meanwhile, arterial blood pressure was significantly lower than both controls and MetS-sedentary rats. These findings suggest that a short-term, low-intensity exercise program can improve cardiac tolerance to I/R injury possibly by ameliorating the high-risk cardiovascular components of the MetS.

Keywords: Cardioprotection; Exercise; Ischemia/reperfusion; Metabolic syndrome; Nitric oxide; Obesity.