Estrogen Metabolism in the Male Dog. Uptake and Disappearance of Specific Radioactive Estrogens in Tissues and Plasma Following Estrone-6,7-3H Administration. Identification of Estriol-16α, 17αin Tissues and Urine1

Estrone-6,7-3H was administered to a group of male dogs, which were then sacrificed at 10, 30 and 120 min. Samples of plasma, liver, kidney, heart, omentum and (in a separate experiment) urine were obtained and analyzed for specific radioactive estrogens. Identification was carried out by column partition chromatography and by co-crystallization with authentic nonradioactive estrogen standards. Estrone and estradiol-17β were found in all tissues, plasma and urine. Preferential concentration of estrone was observed in omentum. There was no preferential concentration of estradiol-17β in any tissue. No 2-methoxyestrone was found in any tissue, plasma or urine. There was some evidence for estradiol-17α in liver, but identification was incomplete. Estriol-16α, 17α was found in all urines in relatively high yield. Only traces of estriol were found in 2 of 4 urines. Small amounts of estriol-16α,17α were found in liver and kidney, but not in other tissues or plasma. No other estriol epimers were found in any tissue or fluid. An increase in the estriol 16α,17α: estrone and estriol 16α,17α: estradiol-17β ratios with time was observed for kidney but not for liver. (Endocrinology82: 500, 1968)