title: The role of inorganic phosphate in the release of Ca2+ from rat-liver mitochondria.
abstract: The effect of inorganic phosphate on Ca2+ retention has been investigated using phosphate-depleted liver mitchondria. Phosphate induces the release of Ca2+ through an efflux route insensitive to ruthenium red. This effect is not due to functional or structural damage, since mitochondria maintain their membrane potential during phosphate-induced Ca2+ efflux. Direct enzymatic measurement of mitochondria pyridine nucleotides has established that changes in their redox state (i.e. increased oxidation) do not play a role in the phosphate-effect. The phosphate-induced Ca2+ efflux requires transport of phosphate out of mitochondria. However, the fluxes of Ca2+ and phosphate do not coincide: the release of phosphate preceeds that of Ca2+.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010710:Phosphates / Q000494:pharmacology*; D051381:Rats; D012430:Ruthenium Red / Q000494:pharmacology
chemical_list: D010710:Phosphates; D012430:Ruthenium Red; D002118:Calcium