Effect of 9α-Fluorocortisol on the Excretion of Urinary Digoxin-like Substance in Normotensive Men

Abstract

In order to investigate the possible role of mineralocorticoid in the regulation of digoxin-like substance (DLS), 9α-fluorocortisol (9-F) was administered to 6 healthy men and urinary exeretion of DLS was measured. The administration of 0.6 mg of 9-F caused slight increases in body weight and blood pressure and significant decreases in urinary Na excretion, plasma renin activity and plasma aldosterone, which indicate the expansion of extracellular fluid (ECF) volume by 9-F administration. Urinary excretion of DLS decreased significantly from the baseline level of 43.3±2.6 (SEM) to 29.8±5.1 (SEM) ng/day; digoxin equiv. after 9-F. These results suggest that a large dose of mineralocorticoid may suppress DLS despite an increase in the ECF volume.