Abstract des Autors

Apart from the catalytic function in a variety of biotransformations, heme-oxygenase (HO-1) is an indicator of oxidative stress and a potent antioxidative enzyme. Is exercise able to affect the expression of HO-1? And furthermore, is there an effect of training on HO-1 expression at rest? Leucocytes of 12 male, trained athletes, taken 24 hours before, 0, 3, and 24 hours after a half-marathon race were immediately stained and analyzed by flow-cytometry, which allowed to focus on the HO-1 expression of lymphocytes, monocytes and granulocytes separately. To compare the results with non-athlete data, leucocytes of 12 male, untrained blood-donors were treated and analyzed in the same way. The percentage of HO-1-expressing cells rose in all cell types examined. All cell types of the athletes showed less HO-positive cells at rest in comparison with those of the control group. As far as the white blood cells are concerned, intensive exercise increased the expression of HO-1. lt is very likely that oxidative stress plays a causal role. These findings may stress the importance of heme-oxygenase in the acute defense of oxidative stress. Lower HO-percentage at rest in trained individuals could be a hint for the secondary role of heme-oxygenase in long-term adaptation. A training induced up-regulation is described for other antioxidative systems like catalase and superoxide-dismutase. This study emphasizes the importance of HO-1 as stress protein due to the acute-phase response shown above. Verf.-Referat