Increase of pro-oxidants with no evidence of lipid peroxidation in exhaled breath condensate after a 10-km race in non-athletes

It is a well-established fact that exercise increases pro-oxidants and favors oxidative stress; however, this phenomenon has been poorly studied in human lungs. Pro-oxidative generation (H₂O₂, NO ₂ ^-), lipid peroxidation markers (MDA), and inflammation (pH) in exhaled breath condensate (EBC) have been determined through data from 10 active subjects who ran 10 km; samples were obtained immediately before, at 20, and at 80 min post-exertion. In EBC, the concentration of H ₂O₂ at 80 min post-exertion was increased. NO₂ ^- concentration showed a tendency to increase at 80 min post-exertion, with no variations in MDA and pH. No variations of NO₂ ^- were found in plasma, while there was an increase of NO ₂ ^- at 80 min post-exertion in the relation between EBC and plasma. NO₂ ^- in EBC did not correlate to plasmatic NO₂ ^-, while it did correlate directly with H ₂O₂ in EBC, suggesting a localized origin for the exercise-related NO₂ ^- increase in EBC. MDA in plasma did not increase nor correlate with MDA in EBC. In conclusion, high-intensity exercise increases lung-originated pro-oxidants in non-athlete subjects with no evidence of early lipid peroxidation and changes in the pH value in EBC.