Effect of Ouabain on Adrenal Potassium Balance in Sheep

A previous study revealed that ouabain caused a marked decrease in aldosterone secretion, but the adrenal K status was not clear from those data. The present study investigated the magnitude and time course of change in adrenal K balance when ouabain was administered into the adrenal arterial supply of the in situ adrenal of conscious sheep. Ouabain at an adrenal arterial plasma concentration of approximately 2.4 X 10(-4) M produced a striking negative adrenal K balance within 10 min of beginning the infusion. The adrenal continued to lose K during the 30-min infusion and for 30 min thereafter. The mean total K loss was 42.3 +/- 7.9 muequiv/adrenal (n = 11). Thirty minutes after ending the ouabain infusion, the adrenal began taking up K but had not recovered its normal K complement by 60 min.