METABOLISM OF STEROID CONJUGATES 3 - METABOLISM OF [6,7-3H]3-HYDROXY-1,3,5(10)-ESTRATRIEN-17-ON [35S]SULFATE

Metabolism of steroid conjugates, III: Metabolism of [6,7-3H]3-hydroxy-l,3,5(I0)-estra-trieN17-on [35S] sulfate. After i.v. administration of [6.7-3H]-estrone [35S]sulfate plasma, skin eluate and 24-hour urine of a 25 year old woman were assayed for labeled free and conjugated estrogens. Whereas the skin eluate contained only 0.06 % of injected 3H-activity, 0.57% were found in the fraction of free steroids and 19.1% in the fraction of conjugated steroids from the 24-hour urine. The latter fraction consisted primarily of steroid glucuronides. From the fraction of sulfoconjugated steroids in plasma, skin eluate or urine double-labeled estrone 3-sul-fate, estradiol 3-sulfate, estriol 3-sulfate or estradiol 3.17β-disulfate could be isolated. Furthermore, in the fraction of polar conjugates from urine also double-labeled estriol 3-sulfate-16α(17β)-glucuronide, as well as single-labeled estradiol and estriol glucuronide were detected. Sulfoconjugated estrogens in plasma exhibited an unchanged isotope ratio 3H/35S as compared to that of the substrate, while the isotope ratio of estrogen sulfates in urine proved to be much higher, indicating a pronounced hydrolysis of sulfoconjugates and resulfurylation of liberated estrogens. © 1969, IEEE. All rights reserved.