Abstract
Mitochondrial ion transport has been studied by many investigators since the early work of Bartley and Davies (1). Passive ion extrusion was observed on aged mitochondria or on fresh mitochondria with valinomycin (2-5). On the other hand, metabolism dependent ion retention (6-8), ion uptake (9-17) and ion extrusion (18-20) have been found on mitochondria. It is suggested that there are some unknown factors which control ion movement in the mitochondria.
Presently, in order to clarify the factor, movement of potassium and magnesium was studied in the mitochondria of the kidney cortex and liver of rats. A metabolism dependent potassium and magnesium ion extrusion was observed in the presence of a respiratory substrate, and this extrusion was converted to retention by further addition of 1.0 mM of ATP. This effect of exogeneous ATP was disccussed.
