Cortisone and cortisol in maternal and fetal blood and in amniotic fluid during the final ten days of gestation in the rabbit.
We have used instant thin-layer chromatography and radioimmunoassay to measure the concentrations of total cortisone (E) and cortisol (F) in the fetal and maternal compartments of the rabbit. The concentration of F in fetal blood increased markedly at day 25; this is just prior to the rapid increase in the surfactant phospholipids in lung tissue in this species. This increase coincided with a peak in the concentration of E and F in the maternal blood and may reflect the maternal levels. There was no 'surge' in the concentration of total F in fetal blood at term. The concentration of E in fetal blood varied between 5 and 15 ng/ml during this last stage of gestation, hence providing ready substrate for the 11 beta-reductase present in lung and other tissues. The concentration of E and F in maternal blood was significantly higher and more variable than that in blood from nonpregnant female rabbits, and there was a pronounced peak in concentration at day 30 (term: 31 days). The concentrations of both E and F in amniotic fluid were lower than those in either maternal or fetal blood until day 30 when the concentration of F increased fivefold to 19.2 +/- 2.58 (mean +/- SEM of 6 samples).
D000653:Amniotic Fluid / Q000032:analysis*; D000818:Animals; D003348:Cortisone / Q000032:analysis* / Q000097:blood; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D005865:Gestational Age; D006854:Hydrocortisone / Q000032:analysis* / Q000097:blood; D011247:Pregnancy; D011817:Rabbits
D003348:Cortisone; D006854:Hydrocortisone