Induction of 2H+/Me2+ exchange in rat-liver mitochondria

The time dependency of CA2+ efflux from Ca2+-loaded rat liver mitochondria has been investigated. The rate of ruthenium-red-insensitive Ca2+ efflux is continuously increased during the retention as a result of induction of an electroneutral H+ Ca2+ exchange system. The activation of the Ca2+ efflux pathway takes place under the constant value of the membrane potential and is accompanied by oxidation of mitochondrial pyridine nucleotides. It has also been found that the ruthenium-red-insensitive H+/Sr2+ exchange occurs in mitochondria during Sr2+-induced oscillation of ion fluxes. The rate of H+/Sr2+ exchange is variable and depends on the stage of the oscillatory cycle.