Ontogeny of cortisol-cortisone interconversion in human tissues: a role for cortisone in human fetal development
Murphy, B.E.
Journal of Steroid Biochemistry 14(9): 811-817
1981
ISSN/ISBN: 0022-4731 PMID: 6946266 Accession: 006034390
While in adult human serum, cortisol (F) is present in higher concentrations than cortisone (E), the reverse has been recognized in fetal serum for 2 decades. To clarify the relationship between biologically active F and its inert metabolite E, the interconversion of these steroids was investigated in various tissues of the human fetus neonate, child and adult. Tissues obtained within 48 h of death or surgery were incubated with 3H F and E at 37.degree. C for 2 h with and without added substrate in the absence of cofactors. Conversion of F to E was highest in placenta > fetal kidney and lung > adult testis and ovary > other fetal tissues, while that from E to F was greatest in adult liver > membranes > adult ovary and testis > term uterus. Activity in either direction was greatly decreased at the time of delivery of both mature and premature infants. Inactivation of F to E in the hemochorial placenta and in the fetus itself may protect the fetus against the growth-inhibiting effects of F, while production of F from E in the membranes and uterine wall contributes to the maintenance of the fetal allograft.