Modulation of antioxidant enzymes and lipid peroxidation in salivary gland and other tissues in mice by moderate treadmill exercise

The current experiments were designed to study the effect of moderate treadmill training exercise on lipid peroxides and antioxidant enzyme activity in various tissues of ICR mice. Three-month-old female mice were trained on a treadmill to run daily from 45 to 50 minutes, at 1 km per hour, 6 days a week for a total of 8 weeks. At the end of the 8-week endurance- training period, both sedentary control (SC) and exercise-trained (ET) mice were sacrificed, and various tissues were collected to measure antioxidant enzyme activity. The results showed weight gain and serum lipid peroxides significantly decreased in ET mice compared to SC mice. Also, although lipid peroxide levels in kidney and salivary glands were found to be significantly decreased in ET mice, these mice showed higher lipid peroxide levels in the liver compared to SC mice. No change was observed in heart and calf muscle tissue of the ET mice. Exercise was also noted to increase superoxide dismutase (SOD) activity in kidney, heart, and calf muscle homogenates. Increases in catalase activity were present in liver, heart, calf muscle, and salivary gland homogenates of ET mice compared to their SC counterparts. Exercise was also shown to increase glutathione peroxidase activity in liver, kidney, and heart homogenates, as well as glutathione transferase activity in liver and salivary gland homogenates. In addition, exercise training was found to increase reduced and total glutathione levels in heart, calf muscle, and salivary gland. These results indicate that moderate exercise is beneficial to the lowering of lipid peroxides and the increasing of antioxidant enzyme activity specifically in the salivary gland, and also in various organs. However, its beneficial effect on elevation of antioxidant enzymes and suppression of lipid peroxide varies from organ to organ.