Effects of aerobic training on oxidative stress and inflammation in rats exposed to controlled emissions of carbon monoxide (CO) and nitrogen dioxide (NO2)

The objective of this study is to determine the effects of isolated exercise and those of repeated exercise on oxidative stress and the inflammatory process following exposure to carbon monoxide (CO) and nitrogen dioxide (NO2).
Material and Method: 15 male Wistar rats, all eight weeks old, were randomly assigned to three groups. CO and NO2 were produced by the combustion of diesel fuel using a device contained in a sealed metal box and supplied with ambient air by a pump. The ranges of CO and NO2 concentrations to which the rats were exposed ranged from 35 to 45 ppm and 0.2 to 0.3 ppm, respectively. The aerobic workouts were performed on a rat treadmill. Blood samples were taken 24 hours after completion of handling at D4, D9 and D14. Variables studied were Malondialdehyde (MDA) and Tumor Necrosis Factor-alpha (TNF-α).
Results: Aerobic endurance training after repeated exposure to CO and NO2 induces at the end of the first training block (D4) a significant increase (p ˂ 0.01) in MDA and TNF-α. On the other hand, the second block (D9) and the third training block (D14) induced a significant decrease (p ˂ 0.01) in these same parameters.
Conclusion: Aerobic exercise practiced in isolation exacerbates the oxidative stress and inflammation induced by exposure to CO and NO2. On the other hand, regular aerobic exercise in a less polluted environment, following five days of recovery, significantly reduces the high levels of oxidative stress and inflammation caused by repeated exposure to automobile pollutants.