The production and aromatization of dehydroepiandrosterone in post-menopausal women

Using infusions of [3H]dehydroepiandrosterone (DHEA) and [14C]oestrogens, the metabolic clearance rates (MCRD) and blood production rates (PDB) of DHEA and the rate of aromatization of DHEA to oestrone and oestradiol were measured in 7 normal post-menopausal women. The mean +/- SEM value for MCRD was 1850 +/- 270 l/day and for PDB was 3.2 +/- 0.6 mg/day. The MCRD value is similar to those reported for young women but PDB is less than those reported for younger women. The mean +/- SEM value for the aromatization rate of DHEA to E1 in 6 women was 0.0058 +/- 0.004 and in 1 woman the aromatization rate of DHEA to E2 was 0.0008. About 30% of the aromatization of DHEA to E1 occurred via the blood pool of androstenedione. However, 20-25% of E1 arose via the aromatization of DHEA to E1 in peripheral tissues without the intermediacy of the blood pool of androstenedione, and thus the peripheral aromatization of DHEA can be an important source of E1 in some women.