Oestrogen Metabolism in the Human Foetus

Abstract

In order to test the validity of a previously advanced hypothesis, that the human foetus actively participates in the oestrogen metabolism of pregnancy attempts were made to introduce different oestrogens into the foetal organism prior to surgical interruption of gestation. Intravenous infusion into the mother of as much as 100 mg of oestriol (oestra-1,3,5(10)-triene-3,16α,17β-triol) resulted in no rise at all in the oestriol concentration of amniotic fluid and only in an extremely limited increase in the conjugated oestriol content of the foetal lungs and livers. It was found that intra-amniotic injection is a most effective way of introducing oestrogen into the foetal organism, since the oestrogen injected is rapidly swallowed (perhaps also aspirated) by the foetus. The administration of 25 mg amounts of 17β-oestradiol (oestra-1,3,5(10)-triene-3,17β-diol) or oestriol by this route resulted in a greatly elevated concentration of conjugated oestrone (3-hydroxy-oestra-1,3,5(10)-triene-17-one) + oestradiol and oestriol, respectively, in a variety of foetal organs, such as the lungs, liver, intestines, and adrenals + kidneys. Especially the lungs seemed to represent a very active site of conjugation, whereas the increase in conjugated oestrogens in the placenta was very limited. Intra-amniotically administered 17β-oestradiol or oestriol rapidly disappeared from the amniotic fluid; it was halved in less than 2 hours and disappeared within 24 hours.

Estrogen formation and binding in the cerebral cortex of the developing rhesus monkey.

“…This may effectively limit exposure of the fetal tissues to the circulating hormone in the same way as binding to plasma proteins is believed to protect the tissues of developing rodents from maternal estrogens (1,27).…”

Die quantitative dünnschichtchromatographische und gaschromatographische Bestimmung von östrogenen

“…Ganz besonders wichtig ist die Östriolausscheidung, die Rückschlüsse auf den Zustand des Fötus erlaubt [2,3,5]. Die Östriolausscheidung in der Schwangerschaft widcrspiegelt den Funktionszustand der Plazenta-Fötus-Einheit [1,4,6,7,8,9,12,13,14,15,16,18].…”

Teratogenic Screening Methods and Their Application to Contraceptive Products

“…With regard to the metabolism in the foetal organism, may I mention that only certain specific sulphurylations (such as the formation of 21-sulphates) are restricted to the foetal adrenals (Diczfalusy 1969), whereas others, such as the sulphurylation of oestrogens occur in most, if not all, foetal tissues (Diczfalusy et al 1961;Diczfalusy 1969).…”