Abstract des Autors

Oxidative stress is known to induce the formation of free radicals followed by an increase in lipid peroxide concentrations. The amount of lipid peroxidation can be evaluated by different biomarkers such as hydroperoxides, MDA (TBARS) and conjugated dienes. The human organism possesses defending mechanisms counteracting the increase of lipid peroxide concentration as e.g. the antioxidant vitamin E. The objective of our investigation was to elucidate the influence of a single bout of exhaustive exercise on serum concentrations of conjugated dienes and vitamin E. We examined 29 trained men before and after (1 h, 24 h) a short triathlon (400 m swimming, 25 km cycling, 4 km running). We determined the concentration of conjugated dienes (photometrically), vitamin E (HPLC) and CK- and LDH-activities in serum. CK-, LDH-activity and concentrations of conjugated dienes were significantly elevated after exercise. There were no correlations to be found between the individual increase of conjugated dienes and the changes in the corresponding CK- and LDH-activity or initial vitamin E concentrations. The concentrations of vitamin E remained unchanged post-exercise. The results underline the observation that exhaustive exercise leads to an increased generation of conjugated dienes. Obviously, the physiological compensating system failed to inhibit the exercise-induced increase in lipid peroxides in serum. Verf.-Referat