METABOLISM OF DEHYDROEPIANDROSTERONE BY CULTURED HUMAN ADIPOSE STROMAL CELLS - IDENTIFICATION OF 7-ALPHA-HYDROXYDEHYDROEPIANDROSTERONE AS AMAJOR METABOLITE USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND MASS-SPECTROMETRY

Studies of the metabolism of dehydroepiandrosterone (DHA) by cultured human adipose stromal cells revealed that the most abundant metabolite detected by HPLC was a polar compound accounting for up to 45% of tot al radioactivity. This metabolite was isolated by chromatography on Li pidex 5000 from the culture medium of breast adipose stromal cells cul tured with unlabelled DHA (5 muM) and identified by combined capillary gas chromatography and mass spectrometry as 7alpha-hydroxydehydroepia ndrosterone (7alpha-OHDHA). In breast adipose stromal cells, the conve rsion of DHA to 7alpha-OHDHA was linear from a substrate concentration of 10 nM to 1 muM. At 1 muM substrate concentration, the formation of 7alpha-OHDHA in four patients ranged from 6.1 to 22.5 ng/10(5) cells/ 24 h. Incubations carried out in primary culture and up to the fifth s ubculture revealed continued formation of 7alpha-OHDHA. Adipose stroma l cells from abdomen, flank and perinephric fat also produced 7alpha-O HDHA from DHA. These studies have shown that 7alpha-OHDHA is a major m etabolite of DHA in human adipose stromal cells. The variability from patient to patient and the magnitude of this conversion suggests that this pathway may play an important role in the peripheral metabolism o f DHA.