Cortisol Secretion Is Mediated by cAMP Adrenocortical Adenomas

We examined the role of PKC in cortisol secretion from adrenocortical adenomas. Isolated cells were prepared from aldosterone producing adenoma (APA, n=5), APA complicated with preclinical Cushing's syndrome (APA+PC, n=1), PC (n=2), and cortisol producing adenoma (CPA, n=5). They were stimulated with 100 nM ACTH, 1 μM forskolin (FS), 1,uM tetradecanoyl phorbol 13-acetate (TPA), and 100 nM angiotensin II (AngII). ACTH was most potent to secret Cortisol. FS also stimulated cortisol secretion, but did less-potently. TPA and AngII also stimulated cortisol secretion significantly in cells from CPA. Furthermore, ACTHand TPA-induced PKCa and 13 translocations from cytosol to membrane were observed in adenoma cells from APA+PC, PC, and CPA. In conclusion, it was suggested that ACTH-induced cortisol secretion may be mediated by both PKC and protein kinase A in adrenocortical adenomas, and that PKC-mediated signal transduction may be involved in ACTHinduced cortisol secretion in CPA.