Rates and Patterns of Excretion of Radioactive Estrogen Conjugates Following the Administration of Estrone-6,7-3H to Male Subjects

Abstract

Estrone-6,7-H3 was administered intravenously to 3 normal males, and the urinary and excretion of radioactive estrone, estradiol-17[beta] and estriol conjugates was analyzed, using solvolysis ("sulfates") and glucuronidase hydrolysis ("glucosiduronates"). There was little or no excretion of unconjugated estrogens. Estrone was excreted as "sulfate" and "gluco-siduronate" in approximately equal amounts, whereas estradiol-17[beta] and estriol were excreted predominantly as "glucosiduronate." Estrone, estradiol-17[beta] and estriol "sulfates" were excreted more rapidly than the corresponding "glucosiduronates." Estriol "glucosiduronate" excretion was not complete after 4 days. The excretion of estrone and estriol "sulfates" and of estrone "glucosiduronate" was in the form of a single exponential, whereas the excretion of estradiol-17[beta] and estriol "glucosiduronates" was a more complex function of time. Evidence is presented that the estriol "glucosiduronate" excretion curve reflects the distribution of this conjugate in 2 or more anatomical pools, one of which may be the biliary-enteric circulation.