Cortisol production by aldosterone-producing adenomas in vitro.

1. In vitro short-term production of cortisol by dispersed tumour and non-tumourous adrenal cortical cells was measured with and without added angiotensin II (AII) or adrenocorticotrophin (ACTH) in adrenals removed from five patients with primary aldosteronism. 2. Aldosterone-producing adenomas (APA) were classified as angiotensin responsive (AII-R) or angiotensin unresponsive (AII-U) based on pre-operative behaviour in vivo. 3. Cortisol was produced by both tumour and cortex in vitro without stimulation, and significantly more cortisol was generated by the cortex. 4. Addition of AII significantly increased cortisol production by both tumour and cortex to an equal extent. 5. Addition of ACTH also significantly increased cortisol production by both tumour and cortex, but tumours were more responsive than cortex. The response to ACTH exceeded the response to angiotensin in both tumour and cortex. 6. There was no obvious difference between AII-R and AII-U APA in terms of cortisol production.