Progesterone Metabolism in an Anencephalic Newborn

Abstract

During pregnancy considerable amounts of placental progesterone enter the maternal as well as the fetal organism ( Z a n d e r and v. M u n s t e r m a n n , 1954; Z a n d e r , 1959, 1961). It was established by previous in vivo investigations that placental progesterone is extensively metabolized by the human f e t u s at relatively early phases of gestation and at the end of pregnancy ( Z a n d e r , 1961, 1962; R u n n e b a u m and Z a n d e r , 1962). Data from Z a n d e r and S o l t h (1953) suggest that the metabolism of progesterone in the newborn is different from that in the adult.In order to obtain more detailed information on progesterone metabolism in the newborn, an anencephalic newborn was perfused with proge~terone-4-'~C and the radioactive material present in the circulating blood and in the tissues was investigated. In this paper data are presented on the circulating radioactive material during and following the perfusion. The data on the analysis of the radioactive material in the tissues will be reported in a second paper by H o 1 z m a n n and Z a n d e r (unpublished results 1965).

Cortisol Binding to Proteins in Plasma in the Human Neonate and Infant

“…By contrast, the fetal plasma exhibits low specific binding capacity for cortisol and in addition contains high levels of competing steroids, able to bind to the same sites. For example, 50% of the placental progesterone production goes t o th: fetus (37), and this steroid has a high affinity for CBG at 37 (1 6, 34). This situation would result in a relatively large proportion of unbound plasma cortisol in the fetal plasma.…”