Effect of regular aerobic exercise on cardiac ischemia-reperfusion injury in the rats

Ischemia/Reperfusion (I/R) injury is one of the most important cardiovascular problems. The aim of this study was to evaluate the protective effects of short term and regular growing long term aerobic exercise on cardiac I/R injury in rats. For this purpose, forty male Wistar rats were randomly divided into four equal groups including: control, I/R, I/R with two weeks of aerobic exercise, and I/R with eight weeks of regular growing aerobic exercise groups. Aerobic exercise was performed 5 times per week on treadmill at speed of 10-25m/min for 10-30 minutes with the slope of 5 degrees. For inducting of I/R injury, left descending coronary artery was clamped for 30 minutes, thereafter blood flow was restored for 2 hours. Blood samples were collected for measurement of cardiac biomarkers, creatinine kinase-MB (CK-MB) and lactate dehydrogenase. Finally, all animals were euthanized for histopathological examination and the assay for myocardial antioxidant status. Microscopically, myocardia of I/R group showed severe degenerative and necrotic changes. Short term aerobic exercise did not alter the tissue damage caused by I/R, while regular growing long term aerobic exercise alleviated myocardial necrotic changes. Regular growing long term aerobic exercise significantly (p