Pettenkofer chromogens in the maternal and fetal circulations: Detection of 3β, 16α-dihydroxy-androst-5-en-17-one in umbilical cord blood

At least part of the precursors for the biosynthesis of estriol may reach the placenta from the maternal or the fetal circulations. This possibility led us to estimate 3β-hydroxy-Δ5-steroids in blood from the umbilical artery and vein and in maternal peripheral blood. Solvolyzed plasma extracts from 12 separate collections were chromatographed on alumina and the fractions examined by means of the modified Pettenkofer reaction. The most abundant of these compounds in maternal plasma was dehydroepiandrosterone. Its concentration in the fetal circulation, although more than double the maternal concentration, was smaller than that of another Pettenkofer chromogen, 16α-hydroxy-dehydroepiandrosterone (3β, 16α-dihydroxyandrost-5-en-17-one), heretofore unrecognized in fetal blood. The differences between the plasmatic concentrations in the umbilical artery and vein suggest a fetal contribution of 16α-hydroxydehydroepiandrosterone to the placenta, presumably to play a role as precursor for the biosynthesis of estriol.