title: Resting state respiration of mitochondria: reappraisal of the role of passive ion fluxes.
abstract: Rat liver mitochondria respiring under resting state conditions in the presence of oligomycin were rapidly blocked with cyanide and the dissipation of the membrane potential, measured with a tetraphenylphosphonium-sensitive electrode, was followed over time. The plot of the rate of membrane potential dissipation versus the actual value of the membrane potential was nonlinear and identical to the plot of resting state respiration (titrated with small amounts of a respiratory inhibitor) versus the membrane potential. The relationship between the respiratory chain activity and the proton-motive force in mitochondria oxidizing succinate with either oxygen or ferricyanide as electron acceptors was also found to be identical. These results are interpreted as an indication that the passive permeability of the inner mitochondrial membrane toward ions is far more significant in maintaining resting state respiration than is the molecular slippage of the pumps in the respiratory chain. These results also confirm the non-ohmic characteristics of the inner mitochondrial membrane.
authors.affiliation: Department of Cellular Biochemistry, Nencki Institute of Experimental Biology, Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Zółkiewska
authors.forename: B
authors.initials: B
authors.lastname: Zabłocka
authors.forename: J
authors.initials: J
authors.lastname: Duszyński
authors.forename: L
authors.initials: L
authors.lastname: Wojtczak
mesh_terms: D000818:Animals; D005292:Ferricyanides / Q000378:metabolism; D007202:Indicators and Reagents; D007425:Intracellular Membranes / Q000187:drug effects / Q000502:physiology; D007477:Ions; D007700:Kinetics; D008314:Malonates / Q000494:pharmacology; D008433:Mathematics; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects; D011190:Potassium Cyanide / Q000494:pharmacology; D011522:Protons; D051381:Rats
chemical_list: D005292:Ferricyanides; D007202:Indicators and Reagents; D007477:Ions; D008314:Malonates; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011522:Protons; C030290:malonic acid; D011190:Potassium Cyanide; C013289:tetraphenylphosphonium