Simultaneous determination of plasma 11-deoxycorticosterone, 18-hydroxy-11-deoxycorticosterone, and aldosterone in man.

A method for simultaneous measurement of 11-deoxycorticosterone (DOC), 18-hydroxy-11-deoxycorticosterone (18-OH-DOC) and aldosterone using 1.0-2.0 ml of plasma has been developed. The present method consists of extracting plasma with dichloromethane, separating the DOC, 18-OH-DOC, and aldosterone from other steroids on a Sephadex LH-20 column, and quantitating each steroid by radioimmunoassay. This method was demonstrated to be sensitive, accurate and precise. In 20 normal male subjects, the mean recumbent level of DOC was 9.1 +/- 3.1 ng/100 ml, on random diet, at 0800 h. The corresponding levels of 18-OH-DOC and aldosterone were 8.2 +/- 3.9 ng/100 ml, and 6.7 +/- 2.6 ng/100 ml, respectively. Plasma levels of these three steroids were measured in several types of adrenocortical disorders associated with hypertension and hypokalemia. Patients with Cushing's syndrome due to adrenocortical hyperplasia, and 17alpha-hydroxylase deficiency had elevated DOC and 18-OH-DOC levels, but showed normal or lower aldosterone levels. Hypersecretion of DOC and 18-OH-DOC may cause the symptoms of hypertension and hypokalemia. Patients with primary aldosteronism had elevated levels of DOC and 18-OH-DOC as well as aldosterone. The former two steroids may be hyperproduced as a precursor of aldosterone.