The activation and oxidation of octanoate and palmitate by rat skeletal muscle mitochondria

• Published in: Biochimica et biophysica acta Vol. 316; no. 2; pp. 124 - 135
• Main Authors: Groot, P.H.E., Hülsmann, W.C.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 23.08.1973
• Subjects: Animals; Caprylates - metabolism; Caprylates - pharmacology; Carbon Radioisotopes; Chromatography, Ion Exchange; Coenzyme A Ligases - antagonists & inhibitors; Coenzyme A Ligases - metabolism; Cytosol; Dinitrophenols - pharmacology; Enzyme Activation; Kinetics; Male; Manometry; Mitochondria, Muscle - drug effects; Mitochondria, Muscle - enzymology; Muscles - cytology; Muscles - enzymology; Oxygen Consumption; Palmitic Acids - metabolism; Palmitic Acids - pharmacology; Polarography; Potassium Chloride - pharmacology; Rats; Ultrasonics
• ISSN: 0005-2760; 0006-3002; 1879-145X
• DOI: 10.1016/0005-2760(73)90002-7

1. 1. Rat skeletal muscle mitochondria can oxidize octanoate just as well as palmitate. The oxidation of both fatty acids is strongly carnitine dependent, which indicates that the fatty acid CoA ester formation (fatty acid activation) is localized on the outer membrane. 2. 2. The palmitoyl-CoA synthetase and octanoyl-CoA synthetase activities were measured in these mitochondria. Palmitoyl-CoA synthetase was inhibited by octanoate while the octanoyl -CoA synthetase was inhibited by palmitate. Both inhibitions seem to be of the competitive type. These results suggest that both fatty acids are activated by the same enzyme. 3. 3. Octanoyl-CoA synthetase in rat skeletal muscle mitochondria was strongly (3 to 4 times) stimulated by the addition of skeletal muscle cytosol or by the addition of a high concentration of salt.