Effects of Exposure of Animals to Oxygen Atmosphere at Low Pressure on Lipid Peroxidation and Antioxidant Defense

: Relatively short-term (2.5 or 5 h) exposure of Wistar rats to oxygen atmosphere at moderate pressure (1.10-1.15 atm) resulted in an increase in LPO level and reduction of antioxidant activity in the blood serum. An increase in malondialdehyde concentration 1 day after termination of the exposure was followed by a decrease in the inhibiting activity of free radical oxidation of liposomal phospholipids induced by Fe(II) ions (100 μm). Malondialdehyde concentration increased by 1.29 times already after 2.5-h exposure and did not changed when the duration of the exposure to oxygen atmosphere was prolonged to 5 h. These data confirm the necessity of using substances potentiating antioxidant defense of the body during exposure to normobaric oxygenation.