CORTICOSTEROID SYNTHESIS IN A CLEAR CELL ADENOMA: A TIME-BASED STUDY

Abstract

SUMMARY The removal of a large clear cell adenoma (67 g.) from a patient in the Cardiff Royal Infirmary presented an opportunity to investigate the relative importance of alternative metabolic pathways to cortisol in adrenal tissue consisting primarily of a single cell type. Experiments were performed in which chopped tumour tissue was incubated simultaneously with [4-14C]pregnenolone and [7α-3H]progesterone for periods of time ranging from 5 to 120 min. The conversion of these precursors to a variety of corticosteroids and intermediates was determined by radioisotope dilution techniques. From the results obtained, it was concluded that progesterone played only a minor role in the transformation of pregnenolone to cortisol in this tissue. It appeared that a large proportion of any progesterone formed from pregnenolone is rapidly metabolized to the 17-deoxycorticosteroids.