Biosynthesis of oestrogen by the early equine embryo proper

摘要: The embryo proper in early equine pregnancy has recently been shown to have a remarkable capacity for metabolism of oestrogens. High concentrations oestrogens yolk-sac fluid could provide substrate local tissues the and this activity significance development. Due high level oestrogen we examined possibility that it also biosynthesise Conceptuses were collected fourth week (n = 23) was separated from extraembryonic incubation with [3H]androstenedione. Steroids recovered media by solid-phase extraction eluted as unconjugated conjugated fractions. Profiles free sulfoconjugated fractions, well phenolic steroids extracted them, obtained chromatography. Oestrone oestradiol seen clearly, indicating biosynthesis, presence more polar products, arising primary oestrogens, gave further evidence capable biosynthesis. Aromatase demonstrated detection tritium loss, 3H2O, incubations (n = 3) [1β-3H]androstenedione. It is suggested its biosynthesis may development vasculature at stage.