Exercise-mediated alteration of protein redox states in plasma : a ossible stimulant for hormetic response

Physical exercise increases the metabolic rate and production of reactive oxygen species subsequent to elevated oxidative phosphorylation required to meet the higher ATP demand. This increased free radical generation could alter the redox state of proteins. In order to gain insight into the altered redox state during exercise, protein carbonyls, 4-hydroxylnonenal (HNE) and 3-nitrotyrosine (3-NT) levels were measured in two groups of young subjects (4 untrained controls and 6 long-distance runners). Plasma was analyzed before and after completing a treadmill run at increasing intensities up to volitional exhaustion. After the exhausting run, protein carbonyl and HNE levels were significantly increased in trained runners but not in controls. However, the protein 3-NT levels did not significantly change in either group. These results suggest that altered protein redox state occurs while running an exhausting run in relation to the physical condition of the subjects involved.