Summary
Distribution and fetomaternal transfer of 6β-hydroxy-cortisol (6β-OHF) was studied
using serial sampling following injection of tritium labelled 6β-OHF into various
fluid compartments in the chronically cannulated unaesthesized pregnant ewe. There
was a rapid transfer of 6β-OHF from the fetal circulation into amniotic fluid and
maternal blood. In contrast, the maternal → fetal transfer of this steroid metabolite
was considerably less. The sequence of appearance of 6β-OHF in fetal blood and amniotic
fluid following injection into maternal blood suggests that this steroid is first
transferred across the placenta to fetal blood before gaining entry into the amniotic
fluid space. The half-lives of 6β-OHF after initial equilibration in maternal plasma,
fetal plasma and amniotic fluid were 2.0 h, 5.1 h and 8.9 h respectively. The amniotic
sac appears to contain a relatively static pool of 6β-OHF and may act as a “trap”
for 6β-OHF in the ovine conceptus.
Key-Words
6β-Hydroxycortisol
-
Pregnancy
-
Fetal-Maternal Transfer
