Steroid metabolism in utero and in the neo-natal period
1. Two steroids were identified for the first time as major steroid components of urine collected from infants and plasma obtained from the umbilical blood vessels. These compounds have the formula 3p,l6|3- dihydroxyandrost-5-en-17-one and 3(3,17a-dihydroxyandrost-5-ene, but their importance in the metabolism of steroids by the foeto-placental unit is not known. 2. A method was developed for measuring steroids in plasma obtained from the umbilical blood vessels and urine collected from infants. This depends upon the separation of steroids by thin-layer chromatography, and their assay on the thin-layer plates by developing colours with various spray reagents and subsequent densitometric scanning. The accuracy and specificity of the method is discussed. 3. This method was used to establish normal ranges for the excretion of several 3|3-hydroxy-A steroids found in urine specimens obtained from infants, and to determine the effects upon the excretion of steroids of administering corticotrophin and human chorionic gonadotrophin to newborn infants. 4. The enzyme defects present in three infants with abnormal adrenal glands were investigated by analysis of steroids in urine specimens obtained from these patients. 5. Several 3(3-hydroxy-A"* steroids were measured in plasma samples prepared from venous and arterial blood obtained from the umbilical cord. The concentrations present in arterial plasma were higher than in the umbilical vein, indicating a net uptake of these steroids by the placenta, where it is thought that they are converted into 3-oxo-A steroids and oestrogens. The relationship between the levels of 3(3-hydroxy-Asteroids in plasma obtained from the umbilical blood vessels and oestrogen excretion by the mother was also investigated.