Reversible effects of fatty acids on respiration, oxidative phosphorylation, and heat production of rat liver mitochondria.
1. Oleic acid at low concentrations (0--70 nmol/mg protein) stimulated mitochondrial state 4 respiration 4-fold, increased the apparent enthalpy change of the respiration per gram atom of oxygen consumed from -112 to -208 kJ/O and completely inhibited ATP synthesis without significant effect on the Mg-ATPase activity of mitochondria. 2. Similar effects on mitochondrial respiratory activities were observed with other fatty acids. 3. Bovine serum albumin (BSA) protected mitochondria from the effects of oleic acid irrespective of the order of addition of oleic acid and BSA to mitochondria. The capacity of BSA to bind oleic acid was calculated to be 3.6--7.1 (mean, 4.9) mol of oleic acid/mol of BSA. 4. The response time of mitochondrial respiration to added oleic acid or BSA was 20--25 s.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002151:Calorimetry; D005227:Fatty Acids / Q000494:pharmacology; D006358:Hot Temperature; D008274:Magnesium; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009829:Oleic Acids / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010085:Oxidative Phosphorylation / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology
D005227:Fatty Acids; D009829:Oleic Acids; D014475:Uncoupling Agents; D012710:Serum Albumin, Bovine; D000251:Adenosine Triphosphatases; D008274:Magnesium