EFFECT OF EXOGENOUS ADENOSINE TRIPHOSPHATE ON EXTRUSION AND RETENTION OF ION IN KIDNEY CORTEX MITOCHONDRIA

Extrusion and retention of potassium and magnesium were studied with rat kidney cortex mitochondria. During incubation at 30°C, potassium and magnesium were extruded from mito chondria in the presence of a substrate. At 0°C, the extrusion was not observed. The extrusion of both ions was suppressed with antimycin A or 2, 4-DNP, and not influenced by oligomycin. Exogeneous ATP reduced the extrusion of both ions, and this effect was markedly reduced by metabolic inhibitors and uncoupler. It is concluded that the extrusion of mitochondrial potassium and magnesium depended upon metabolism, and exogeneous ATP controlled both ions' movement. Similar phenomena were observed in liver mitochondria. © 1969, The Japanese Pharmacological Society. All rights reserved.