Abstract: The objective was to investigate if melatonin is related with the decrease of MDA by pinealectomy mice during long term aerobic exercise. Pinealectomied 12-month-old mice were divided into three groups: the control, the swimming-60-min and the 60-min with 3% body mass; and normal mice also were divided three groups in the same way. After eight weeks swimming, all animals were killed, and their MDA levels in serum were assayed. Results: In male mice MDA decreased significantly in normal mice than in the pinealectomied in the swimming-60-min and the swimming-60-min with 3% body mass. while in female mice, the swimming-60-min group has shown the same results as above, but in the swimming-60-min with 3% body weight group the level MDA in pinealectomied group decreased significantly than in the normal group. Conclusion: long term suitable intensity aerobic exercise can enhance the activity of antioxidase, and it is related with stimulating pineal and releasing melatonin.

Key words: swimming|pinealectomy|melatonin