Estrone biliary excretion

Adlercreutz H. Studies on oestrogen excretion in human bile. Acta Endocrinol. Suppl. (Copenh). 42(Suppl 72), 1-220, 1962. [63b] Sandberg AA, Kirdani RY, Back N, Weyman P, Slaunwhite WR. Biliary excretion and enterohepatic circulation of estrone and estriol in rodents. Am. J. Physiol. 213(5), 1138-1142, 1967. 

Early work on the estimation of the amounts of steroids excreted in bile depended on either biological assay or the determination of a f< v known metabolites. Neither method probably estimated all the biliary material. Thus, several investigators found values ranging from I to 95% of the dose for the biliary excretion of estrone or estradiol in the dog, when th(i bile was assayed for estrogenic activity (Caritarow et al., 1942a,b Longwell and McKee, 1942 Pearlman et al., 1945, 194S). However, the availability of C-Iabeled steroids has made it possible to study the meta ... 

The biliary excretion of steroids in humans differs from one steroid to another (Table I), The factors which decide which steroid will be preponderantly excreted in the bile and which will not, have remained unknown. Thus, estradiol and estrone (Ei) appear to be predominantly excreted in the bile, whereas estriol (E ) is only excreted to the extent of about 25% (Sandberg and Slaunwhite, 1965). The hepatic intracellular factors which govern biliary excretion of steroids and their conjugates remain unknown, even though it is possible that dieonjugates are preferentially excreted in the biliary system. For example, the bulk of estriol is present in the bile... 

The biliary patterns of estrone and estradiol present a much more complicated picture, because there appears to be extensive metabolism concomitant with conjugation. This became evident in the extensive investigation by Adlercreutz (1962a, b, 1964 1965 Adlercreutz et al., 1960) and Adlercreutz and Luukkainen (1965) of the biliary excretion of estrogens in humans. A rapid conversion in the liver of estradiol to estrone and... 

Miyazaki et al. (1969) obtained similar results usir labeled estrone, but they found important variations betw cen two patients. In one, no. V-acetyl-glucosaminide could be found. Furthermore, a considerable amount of the excreted tritium label was in the form of a compound having a phenolsulfate and another conj ugating group which was hydrolyzed by hot acid, but not by the customarily employed enzymes or by solvolysis. In unpublished work, Miyazaki el al. found that the biliary pattern after injection of radioactive estradiol differed only in quantitative aspects from that observed in patients injected with estrone. 

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