METABOLISM OF 17BETA-ESTRADIOL-6,7-3H-17-GLUCOSIDURONATE BY HUMAN FEMALE (1)

17β-Estradiol-6, 7-3H-17-glucosiduronate was injected intravenously into 2 normal young females. In one, 17β-estradiol-4-14C was simultaneously administered by the same route. Most of the 3H was excreted in 48 hr., the main urinary metabolites being estrone and 17β-estradiol which were liberated from conjugation by β-glucuronidase hydrolysis. These 2 steroids occurred in a ratio of about 1:1 and accounted for more than 80% of identified 3H-metabolites. Estriol accounted for only 3% and other 16-oxygenated metabolites were of minor quantitative significance as was 2-methoxyestrone. Smaller amounts of each steroid were liberated from conjugation by solvolysis after β-glucuronidase incubation. When 17β-estradiol-4-14C was administered along with the glucosiduronate, urinary 2-methoxyestrone, estrone and 17β-estradiol 'glucosiduronates' were produced to a greater extent from the injected conjugate than from the free steroid. This was also true of 17β-estradiol liberated by solvolysis. 2-Methoxyestrone and estrone liberated by solvolysis had 3H/14C ratios similar to that injected whereas all of the 16-oxygenated metabolites, regardless of conjugation, were formed preferentially from injected 17β-estradiol. © 1969.