Effects of various time courses of endurance training on antioxidant enzymes activity in rat Serum

Due to the importance of antioxidative system and its effective intervention on cascade reactions of free radicals، this study was run to determine the alterations in antioxidant enzymes activity Superoxide dismutase (SOD)، Catalase (CAT)، and Glutathione peroxidase (GPX) after various time courses of endurance training in rat serum. In this study، 62 male Wistar rats were selected randomly and were divided into 3 control (n1=10، n2=10، n3=11) and 3 experimental (n1=10، n2=10، n3=11) groups. Experimental rats trained for 6، 9 and 12 weeks، running for 5 days/week on treadmill with initial speed of 10 m/min for 10 minute، which was gradually incrased to reach the ultimate speed of 25 m/min for 60 minute. For control groups، the protocol was walking on treadmill with the speed of 10 m/min for 3 days/week. After each course (6، 9 and 12 w)، rats were anesthetized and serum samples were collected. Determination of antioxidant enzymes activity was done using Cayman chemical company kits (MI، USA)، using enzymatic color assay method. The results were analyzed by t - test (α=0. 05). The results of this study showed that 6، 9 and 12 weeks of endurance training had no significant effects on Serum SOD and GPX activity، but 9 weeks of endurance training increased the activity of CAT significantly (CAT activity in experimental group was 24. 09±2. 43 U/mL while it was 18. 76 ± 3. 81 U/m in the control group، p ≤0. 05). Findings of this study suggest that 9 weeks of moderate endurance training can increase CAT activity because of increment in reactive oxygen species (ROS) generation، but after continuing the exercise for 12 weeks، it can turn back to the initial levels، maybe because of an adaptation in enzymatic antioxidant system after 12 weeks.