Comparative studies on the effects of linoleate and methyl linoleate and their hydroperoxides on the respiration and reactivities of rat heart mitochondria.
Linoleate hydroperoxide and linoleate at concentrations of 100-140 nmol-mg protein activated state 4 respiration of rat heart mitochondria 4.2-fold, increased the apparent enthalpy change of the respiration per gram atom of oxygen consumed from -148 to -226 kJ/O and completely inhibited oxidative phosphorylation. Methyl linoleate hydroperoxide or methyl linoleate did not show the same effects. Further addition of linoleate hydroperoxide or linoleate induced oligomycin-insensitive Mg-ATPase to a level 5 or 2 times, respectively, that obtained with 120 muM dinitrophenol, accompanied by clearing of the mitochondrial suspension and release of malate dehydrogenase from the matrix. Methyl linoleate hydroperoxide had the same effects except that the induced Mg-ATPase activity retained oligomycin sensitivity. Methyl linoleate did not show either effect.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D002151:Calorimetry; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D008041:Linoleic Acids / Q000494:pharmacology*; D008054:Lipid Peroxides / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D010085:Oxidative Phosphorylation / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats
D008041:Linoleic Acids; D008054:Lipid Peroxides; C008464:methyl linoleate hydroperoxide; C005575:methyl linoleate; C008285:linoleic acid hydroperoxide; D000251:Adenosine Triphosphatases; D008274:Magnesium