caa a22 4500 469054026 CHVBK 20180323132838.0 cr unu---uuuuu 170328e19920101xx s 000 0 eng 10.1007/BF01466268 doi (NATIONALLICENCE)springer-10.1007/BF01466268 Effect of carnitine loading on long-chain fatty acid oxidation, maximal exercise capacity, and nitrogen balance [Elektronische Daten] [O. Heinonen, J. Takala, M. Kvist] Summary: Carnitine has a potential effect on exercise capacity due to its role in the transport of long-chain fatty acids into the mitochondria forβ-oxidation, the export of acyl-coenzyme A compounds from mitochondria and the activation of branched-chain amino acid oxidation in the muscle. We studied the effect of carnitine supplementation on palmitate oxidation, maximal exercise capacity and nitrogen balance in rats. Daily carnitine supplementation (500 mg - kg−1 body mass for 6 weeks) was given to 30 rats, 15 of which were on an otherwise carnitine-free diet (group 1) and 15 pair-fed with a conventional pellet diet (group II). A control group (group III,n = 6) was fed ad libitum the pellet diet. Palmitate oxidation was measured by collecting14CO2 after an intraperitoneal injection of [1-14C]palmitate and exercise capacity by swimming to exhaustion. After carnitine supplementation carnitine concentrations in serum were supranormal [group I, total 150.8 (SD 48.5), free 78.9 (SD 18.4); group II, total 170.9 (SD 27.9), free 115.8 (SD 24.6) gmol·1−1] and liver carnitine concentrations were normal in both groups [group I, total 1.6 (SD 0.3), free 1.2 (SD 0.2); group II, total 1.3 (SD 0.3), free 0.9 (SD 0.2) μmol·g−1 dry mass]. In muscle carnitine concentrations were normal in group I [total 3.8 (SD 1.2), free 3.2 (SD 1.0) μmol · g−1 dry mass] and increased in group II [total 6.6 (SD 0.5), free 4.9 (SD 0.9) μmol·g−1 dry mass]. Despite the difference in muscle carnitine concentrations there were no differences among the groups in cumulative palmitate oxidation after 3 h [group I, 39.7 (SD 11.6)%, group II, 29.6 (SD 14.0)%; group III, 36.5 (SD 10.8)% of injected activity] or swimming time to exhaustion [group I, 9.7 (SD 2.9); group II, 8.4 (SD 3.6); group III, 7.1 (SD 2.8) h]. A borderline increase in nitrogen balance was observed in group II. We concluded that increasing carnitine tissue concentrations by carnitine supplementation had no effect on palmitate oxidation and maximal exercise capacity in the rats studied. Springer-Verlag, 1992 L-Carnitine supplementation nationallicence Fatty acid metabolism nationallicence Muscle metabolism nationallicence Nitrogen balance nationallicence Prolonged submaximal exercise nationallicence Heinonen O. Paavo Nurmi Center, Sports Medical Research Unit and Department of Physiology, University of Turku, Kiinamyllynkatu 10, SF-20520, Turku, Finland aut Takala J. Critical Care Research Program, Department of Intensive Care, Kuopio University Hospital, Kuopio, Finland aut Kvist M. Paavo Nurmi Center, Sports Medical Research Unit and Department of Physiology, University of Turku, Kiinamyllynkatu 10, SF-20520, Turku, Finland aut European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/1(1992-01-01), 13-17 0301-5548 65:1<13 1992 65 421 https://doi.org/10.1007/BF01466268 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01466268 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heinonen O. Paavo Nurmi Center, Sports Medical Research Unit and Department of Physiology, University of Turku, Kiinamyllynkatu 10, SF-20520, Turku, Finland aut NATIONALLICENCE 700 1- Takala J. Critical Care Research Program, Department of Intensive Care, Kuopio University Hospital, Kuopio, Finland aut NATIONALLICENCE 700 1- Kvist M. Paavo Nurmi Center, Sports Medical Research Unit and Department of Physiology, University of Turku, Kiinamyllynkatu 10, SF-20520, Turku, Finland aut NATIONALLICENCE 773 0- European Journal of Applied Physiology and Occupational Physiology Springer-Verlag 65/1(1992-01-01), 13-17 0301-5548 65:1<13 1992 65 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer