Effect of Exercise on Myocardial Ischemic-reperfusion Injury in Sprague- Dawley Rat Model

Globally, cardiovascular disease is the leading cause of death. Of all the spectra of cardiovascular ailments, myocardial infarction (MI) contributes the biggest proportion of mortality. MI results when blood flow to the myocardium is interrupted, thus, is routinely treated by reperfusion therapy, a strategy that may cause ischemic reperfusion injury.  Presently, this injury lacks effective treatment measures; therefore, there is need for more investigation to devise its preventive measures. The current study sought to investigate the effect of varying intensities of exercise on myocardial ischemic reperfusion injury. Twenty male Sprague Dawley rats were divided into 4 groups (N = 5). Three of these were subjected to varying intensities of exercise 21 days. One group served as a control. Ischemia and reperfusion (I &R) procedure was performed on Langendorf perfused hearts and contractile function was recorded during the pre-ischemic and post ischemic periods. These recordings were then compared to assess the degree of myocardial recovery after I & R. Groups were compared using ANOVA (α=0.05). Results showed that there were statistically significant differences between groups in left ventricular developed pressure (P=0.04), maximum rate of contraction (P=0.036), maximum rate of relaxation (P=0.04) and heart rate (p=0.041). Moderate intensity exercise may be having protective effects against ischemic reperfusion injury (IRI). This effect was demonstrated in the current study by improved recovery of left ventricular contractile function following myocardial ischemic-reperfusion injury in the in the group subjected to moderate intensity exercise.