DOUBLE ISOTOPE ASSAY OF ALDOSTERONE, CORTICOSTERONE AND CORTISOL IN HUMAN PERIPHERAL PLASMA

Abstract

SUMMARY A double isotope derivative assay technique for the simultaneous estimation of aldosterone, corticosterone and cortisol in human peripheral plasma is described. With this method, concentrations of the corticosteroids in plasma from adrenalectomized subjects were not significantly different from zero. Further evidence of specificity for aldosterone was obtained by measuring the disappearance rate of a single intravenous injection of unlabelled aldosterone from peripheral plasma, by demonstrating a rapid rise in aldosterone concentration in normal subjects acutely depleted of sodium, and by a comparison of aldosterone levels in patients with primary aldosteronism before and after surgical treatment. A study has also been made of the variation of the ratio of cortisol to corticosterone in normal subjects and of the effect upon this ratio of corticotrophin administration and haemorrhage.