Influence of Acute Ozone and Hypobaric Hypoxia Exposure on the Tissue Oxidant/antioxidant Balance in Physical Exercise
Abstract
Aims. The influence of acute O 3 and hypobaric hypoxia exposure on tissue redox reactivity during rest and exercise conditions was studied in the brain, myocardium, lungs and striated muscles.
Material and methods. The investigation was performed in 3 groups of white male Wistar rats: group I – control group, sedentary rats under normoxia conditions; group II – sedentary rats exposed to acute combined stress: acute O 3 + hypobaric hypoxia; group III – animals exposed to acute combined stress, followed by exercise. Exposure was simulated in the hypobaric chamber for 3 days, 20 hours a day, at 2500 m. Ozone exposure was performed for 3 days, 5 min daily. Group III was trained daily for 3 days under normoxia conditions, by the swimming test. In order to measure the indicators of the oxidant/antioxidant (O/AO) balance, on day 3 tissue samples were taken from the brain, myocardium, lungs and femoral quadriceps muscle.
Results. Animals undergoing physical exercise after acute combined stress exposure have a significant increase in oxidative stress (OS) in the lungs compared to controls. In the myocardium and striated muscle, there are OS changes similar to those found in sedentary animals exposed to combined stress. In the brain, there is a significant decrease in OS simultaneously with a significant decrease in AO defense compared to both the control group and the sedentary group exposed to combined stress.
Conclusions. Physical exercise performed after acute O 3 and hypobaric hypoxia exposure induces significant changes in the O/AO balance in pulmonary, myocardial and brain tissue. Major adaptive changes occur in the lungs, where OS and AO defense increase simultaneously.