Steroids and Sterols in Umbilical Cord Blood1

Abstract

An investigation of 2 pools of umbilical cord blood by means of paper, column, thin-layer and gas-liquid chromatography has led to the detection of 23 steroids and of 5 sterols, the criteria for the identification of each of which are specified. The majority of these compounds appeared to exist in blood as sulfo-conjugates, recoverable by a transesterification procedure. The majority of the steroids and all 5 sterols were found to be digitonin-precipitable, Δ5-3β-hydroxy compounds. These findings, and the results of experiments designed to measure total plasma Δ5-3β-hydroxysteroids and ketosteroids in young infants, are interpreted to indicate that the origin of the Δ5-3β-hydroxysteroids detected in umbilical cord blood is the fetal zone of the adrenal cortex. The fetal zone appears to be markedly deficient in 3β-hydroxysteroid dehydrogenase activity. The relationship of this enzymatic deficiency to cortisol synthesis and of cortisol metabolism to the intrauterine development of the fetal zone of the adrenal are discussed