Comparative Fate of Estrone and Estrone Sulfate in Man

Estrone-14C and estrone sulfate-3H were simultaneously injected into a 37-yr-old woman and disposition of the two isotopes was followed. The products of estrone sulfate were excreted in urine more rapidly and to a greater extent than those of the coadministered estrone. Estrone was converted to estrone and estradiol glucuronides to a much greater extent than its sulfate conjugate. Estrone sulfate on the other hand contributed more to the urinary estrone and estradiol sulfates. All of the other metabolites irrespective of their conjugation contained equal amounts of both isotopes and were therefore most probably biosynthesized after equilibration of the dose. It is likely that estrone sulfate rather than estrone is the precursor of these compounds.