oligomycins and dihydrolipoic-acid

Investigations with dihydrolipoic acid in rat heart mitochondria and mitoplasts reveal an activation of ATP-synthase up to 45%, whereas ATPase activities decrease by 36%. In parallel with an increase in ATP synthesis oligomycin-sensitive mitochondrial -SH groups are activated at 2-4 nmol dihydrolipoic acid/mg protein. ATPase activation by the uncouplers carbonylcyanide-p-trifluoromethoxyphenylhydrazone and oleate is diminished by dihydrolipoic acid, and ATP synthesis depressed by oleate is partially restored. No such efficiency of dihydrolipoic acid is seen with palmitate-induced ATPase activation or decrease of ATP synthesis. This indicates different interference of oleate and palmitate with mitochondria. In addition to its known coenzymatic properties dihydrolipoic acid may act as a substitute for coenzyme A, thereby diminishing the uncoupling efficiency of oleate. Furthermore, dihydrolipoic acid is a very potent antioxidant, shifting the -SH-S-S- equilibrium in mitochondria to the reduced state and improving the energetic state of cells.

Topics: Adenosine Triphosphatases; Adenosine Triphosphate; Animals; Atractyloside; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; Female; Kinetics; Mitochondria, Heart; Oleic Acid; Oleic Acids; Oligomycins; Oxidative Phosphorylation; Palmitic Acid; Palmitic Acids; Rats; Rats, Inbred Strains; Sulfhydryl Compounds; Thioctic Acid