The metabolism of radioestrone in the rat.

Abstract

DURING the period of twenty-five years since the isolation of the first crystalline estrogen many experiments on the metabolism of estrogens have been reported. Since a number of reviews (Doisy et al., 1942; Heard, 1949; Lieberman and Teich, 1953) have considered this subject, only a few points which are closely relevant to the experiments reported in this paper will be mentioned. Most investigators studied the excretion of estrogens in urine, but the low recoveries (5–20%) of administered estrogenic activity led others to search for the unaccounted for estrogen. The recovery of some additional estrogenic activity in feces (Siebke and Schuschania, 1930; Levin, 1945; Dingemanse and Laqueur, 1937; Dorfman, 1937), led to the examination of bile (Longwell and McKee, 1942; Cantarow et al., 1942; Pearlman et al., 1948). However, the amounts detected in dog bile were still insufficient to account for the missing estrogen (Longwell and McKee, 1942; Pearlman et al., 1948).