CONCERNING THE FUNCTION OF THE FETAL ZONE OF THE HUMAN ADRENAL GLAND1

Abstract

A brief review of the normal development of the fetal zone of the human adrenal gland is given and evidence presented indicating pre-natal atrophy of this zone in the second half of gestation in anencephaly. Chemical analysis of extracts of fetal adrenal glands shows the occurrence of weak androgenic steroids and a sodium-retaining factor. The concentration of these steroids is higher in smaller fetuses and it is approximately equal in the male and female fetus. In older fetuses the glands contain small amounts of 17-hydroxycorticosterone. The findings suggest that the C19-steroidogenesis is limited to the fetal zone of the adrenal cortex versus C21-steroid production being performed by the definitive cortex. The factors are discussed which are of probable importance for the maintenance of the fetal zone in intrauterine life. It is suggested that chorionic gonadotropins are responsible for its maintenance during the first 20 weeks of gestation. Thereafter, luteinizing hormone from the fetal pituitary, stimulated by chorionic estrogens, is believed to replace the chorionic gonadotropic stimulus.