Metabolism of exogenous 4- and 2-hydroxyestradiol in the human male.

摘要: Abstract The metabolic fate of the isomeric catecholestrogens 4-hydroxyestradiol (4-OHE 2 ) and 2-hydroxyestradiol (2-OHE was studied to elucidate possible differences in their metabolism as an explanation for different bioactivities. Healthy young men ( n = 3 each) were infused (90 min) with 4-OHE (60 μg/h) or 2-OHE (100 μg/h). main metabolites determined plasma urine before, during after infusion. Unconjugated conjugated steroids, latter hot acid hydrolysis, subjected chromatography on LH-20 columns measured by specific RIAs. During infusion reached significant concentrations whereas so rapidly metabolised that its levels remained virtually undetectable spite a higher rate. dominated direct conjugation, methyl ether formation. These findings corroborated urinary excretion rates: first hours afterwards, mainly excreted 4-hydroxyestrone, while predominantly 2-methyl 2-hydroxyestrone ether.