the effects of moderate-intensity interval training on the resistance to induced cardiac ischemia in adult male rats

Background and Objectives: Myocardial infarction is one the major causes of mortality in the world. The purpose of this study was to investigate the effects of moderate-intensity interval training on the level of resistance to induced cardiac ischemia in male adult rats. Methods: In this study, 16 adult male Wistar rats were randomly divided into two groups of 8 mice: Control and moderate-intensity interval training (MIIT). At the end of 16th week of the training, all rats intraperitoneally received isoproterenol (dose, 85mg/kg) for 2 consecutive days, then cardiac function parameters [heart rate, diastolic blood pressure (DBP), systolic blood pressure (SBP), left ventricular±dp/dt max], Biochemical indicators of tissue damage (heart tissue CTnI and TNF-α) were measured; also, the extent of heart tissue damage was evaluated by histopathological examination. The data were analyzed using nonparametric Mann-Whitney test and independent t-test. The significance level was considered as p≤0.05. Results: No significant differences were seen between the groups in any of the cardiac function parameters [HR (p<0.130), SBP (p<0.48) and DBP (p<0.72)]. However, other cardiac function parameters including left ventricular±dp/dt max in the exercise group was significantly different from the control group (p<0.01). The heart tissue CTnI in the exercise group was significantly higher than the control group (p<0.009). The heart tissue TNF-α in the exercise group was significantly lower than the control group (p<0.029). Histopathological examinations showed the positive effect of exercise protocol on the reduction of tissue damage in ischemic (p<0.003). Conclusion: The results showed that moderate-intensity interval training has protective effects against cardiac damage caused by injection of isoproterenol.