The response of corticotropin and adrenal steroids to desmopressin stimulation in patients with various forms of hypercortisolism.

OBJECTIVE The purpose of this study was to evaluate the direct action of desmopressin (agonist of vasopressin) on the hypophysis and the three zones of the adrenal cortex in patients with different forms of hypercortisolism. DESIGN Forty-three patients with hypercortisolism-21 with Cushing's disease (14 females, 7 males), 11 with extrapituitary, ectopic tumours (5 females, 6 males), and 11 with ACTH-independent Cushing's syndrome (6 females, 5 males)-were evaluated. The response of the pituitary and adrenal glands was assessed by measuring plasma levels of adrenocorticotropic hormone (ACTH), cortisol, aldosterone, and dehydroepiandrosterone sulfate (DHEAS) at baseline and at 15, 30, 60, 90, and 120 min after the administration of desmopressin. RESULTS We observed two main modes of secretory response: (1) elevation of the ACTH level followed by a rise of one, two or all three adrenal steroids, and (2) ACTH-independent elevation of adrenal steroids in various combinations. CONCLUSION In a number of patients with hypercortisolism, the adrenal cortex responded to desmopressin administration by enhanced synthesis and secretion of glucocorticoids (cortisol), mineralocorticoids (aldosterone), and adrenal androgens (DHEAS) without a concomitant rise in ACTH. These findings suggest the presence of "ectopic" vasopressin receptors in the human adrenal cortex.