Effect of endothelin-1 in man: impact on basal and adrenocorticotropin-stimulated concentrations of aldosterone.

The effect of exogenous endothelin-1 [2 pmol (5 ng)/kg.min for 15 min, followed by 1 pmol (2.5 ng)/kg.min for 105 min] on basal and ACTH (250 micrograms, i.v.)-stimulated plasma concentrations of aldosterone, cortisol, testosterone, corticosterone, and 18-hydroxycorticosterone was investigated in a group of healthy male volunteers (n = 6). Plasma concentrations of aldosterone remained unchanged during a placebo experiment (i.e. in the absence of both exogenous ACTH and of endothelin-1). In the absence of exogenous ACTH, the i.v. administration of endothelin-1 did not influence plasma concentrations of aldosterone. The i.v. administration of 0.25 mg ACTH induced a rise in plasma concentrations of aldosterone from a basal value of 152.6 +/- 38.8 to 362.6 +/- 77.7 pmol/L. This ACTH-induced rise was markedly augmented (P < 0.01) by the concomitant administration of endothelin-1, when peak plasma concentrations of aldosterone of 632.5 +/- 230.2 pmol/L were observed. Basal and ACTH-stimulated concentrations of cortisol, corticosterone, and 18-hydroxycorticosterone were unchanged by the concomitant infusion of endothelin-1. Thus, exogenous endothelin-1 influences adrenal function in healthy men by selectively augmenting the ACTH-induced secretion of aldosterone.