Abstract
Extract: Three pregnant ewes and their fetuses, in utero, were infused constantly with 14C-cortisol and 3H-cortisol. The maternal concerntrations of cortisol in plasma were 5.24±1.15 μg/100 ml and the fetal concentrations in plasma were 2.39±0.25 μg/100 ml. Metabolic clearance rates were estimated to have a mean of 1,397 liters/24 h in the ewes and 92 liters/24 h in the fetuses. The mean rates of blood production for the ewe and the fetus were 73.6 and 2.14 mg/24 h, respectively. Application of the theoretical model presented, allowed us to calculate the contribution the mother was making to the cortisol concentration in the plasma of the fetus and vice versa. We also calculated the ratio of relative resistance for transplacental passage of cortisol.
Speculation: From the model proposed, it was calculated that the fetus contributed very little to the maternal cortisol levels. In two experiments, more than 60% of the fetal origin, while in another experiment, almost all the cortisol was produced by the fetus. We speculate, therefore, that a ‘plcental barrier’ exists in sheep during pregnancy. The physiological role of this barrier remains to be determined.
Similar content being viewed by others
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Beitins, I., Kowarski, A., Shermeta, D. et al. Fetal and Maternal Secretion Rate of Cortisol in Sheep: Diffusion Resistance of the Placenta. Pediatr Res 4, 129–134 (1970). https://doi.org/10.1203/00006450-197003000-00003
Issue Date:
DOI: https://doi.org/10.1203/00006450-197003000-00003