Lipid peroxidation and antioxidant defense systems in humans exposed to hypergravity

Nine subjects aged between 25 and 45 years participated in the studies of the effects of directional hypergravity (+G) at endurance limits: +G x (chest–back) at 8.30 ± 0.30 g, and +G z (head–pelvis) at 6.51 ± 0.28 g. Blood samples were collected seven days prior to the rotation test to determine biochemical background levels, and 1 h, one day, and seven days after centrifugation. Blood serum was analyzed for lipid peroxidation (LPO) products (diene conjugates, malone dialdehyde, and Schiff bases) and for antioxidant defense system (ADS) components, including tocopherol, glutathione peroxidase (GP) and catalyze activities, and overall antioxidant activity. Exposure to either +G x or +G z resulted in inhibition of LPO. The effect was more pronounced upon exposure to +G z . According to our results, ADS activation can be attributed to water-soluble GP and catalase. However, a certain decline in LPO intensity can be due to a shift in the biomembrane phase towards greater viscosity.