FETAL-MATERNAL ENDOCRINE INTERRELATIONS: THE HYPOPHYSEAL-ADRENAL SYSTEM1

Abstract

Adrenalectomy of pregnant rats resulted in a highly significant increase in fetal weight (P< .001) Hypophysectomy of pregnant animals prior to adrenalectomy abolished this increase. Hypophysectomy alone had no effect. None of these procedures produced an alteration in fetal adrenal cholesterol concentration. Hypophysectomy of the mother significantly (P< .02) reduced fetal adrenal ascorbic acid concentration, but in the other groups it remained unchanged when compared to controls. Pregnancy resulted in a reduction in the concentrations of maternal adrenal cholesterol and ascorbic acid. The conceptus partially maintained the maternal adrenal glands in the absence of the maternal pituitary in terms of weight, cholesterol concentrations and ascorbic concentration. It is concluded that: (1) the fetal adrenal hypertrophy attendant upon adrenalectomy of the mother is not mediated by the fetal pituitary as previously suggested, but is due to an increased secretion of ACTH by the maternal pituitary, (2) under experimental conditions employed maternal ACTH does cross the placenta, (3) the fetus or the placenta or both produce sufficient quantities of an adrenocorticotropin to influence the maternal adrenal gland in the absence of the maternal hypophysis.