Basal and ACTH-stimulated cortisol and aldosterone release from adrenocortical adenomas in vitro.

Basal and ACTH-stimulated release of aldosterone and cortisol was studied in slices of adrenocortical adenomas and adrenal cortex from 16 consecutive patients with Conn's syndrome (n = 7), Cushing's syndrome (n = 5) or no signs of steroid hypersecretion (n = 4). Clinical data were reviewed and histologic examination was repeated. The adrenal cortex and all tumours but one (non-hyperfunctioning) secreted cortisol. Cortisol release increased after addition of ACTH in 13/15 tumours and all cortex slices. Aldosterone was secreted from the adrenal cortex in all patients and was increased by ACTH in 75% of the tissue specimens. Adenomas from patients with hyperaldosteronism showed the highest basal aldosterone secretion. This secretion was further increased by ACTH. Tumours from patients without signs of corticosteroid excess also released steroids and responded to ACTH. It is concluded that in vitro studies of steroids released from adrenocortical tumours contribute to their diagnostic and functional evaluation.