Potassium ion stimulation of oxidative phosphorylation by brain mitochondria

Abstract

Potassium ion is a specific stimulant of the respiration of brain slices and of brain mitochondria ( Hertz & Clausen, 1963; Sugawara & Utida, 1961). Recently, Utida and Sugawara (1963) have shown that the potassium ion stimulation of mitochondrial respiration is inhibited by ouabain. They conclude that the stimulation of respiration is the result of activation of a sodium-potassium activated ATPase similar to that first reported by Skou (1957) and later demonstrated in brain microsomes by Jarnefelt (1961) and Deul and McIlwain (1961). This paper reports a specific stimulatory effect of the potassium ion on oxidative phosphorylation by rat brain mitochondrial preparations. The rates of both oxygen uptake and phosphate esterification are increased and the control of respiration by the presence of ADP is improved by the addition of optimal concentrations of potassium.