Abstract des Autors

As free carnitine (C) and the inhibition of carnitine acyltransferase I (CAT-I) should avoid the intramitochondrial fatty acid (FA) overload and thereby improve mitochondrial membrane metabolism, 15 male endurance athletes were tested in a double blind endurance stress test (60 min, 65% VO2max) before and after application of carnitine and CAT-I inhibitor. After 7 days of 6 g L-carnitine/d, no significant change of metabolic or respiratory parameters were observed. In contrast, inhibition of CAT-I (1x100 mg Etomoxir R, Byk-Gulden, Konstanz) significantly reduced the production of CO2 at rest as well as during exercise. Therefore, it has to be supposed that this CAT-I inhibitor and not carnitine supplementation itself prevents intramitochondrial accumulation of long-chain acyl-carnitines in healthy individuals. This effect is of special interest in metabolic disorders of FA oxidation. Verf.-Referat