SOME EXPERIMENTS ON ROLE OF FETAL PITUITARY IN MATURATION OF FETAL ADRENAL AND INDUCTION OF PARTURITION IN SHEEP

The effect of repeated increases in plasma ACTH on the production of corticosteroids and androstenedione in the sheep fetus was investigated. Elevation of fetal plasma ACTH for up to 2 h every 24 h by repeated periods of hypoxia increased the output of cortisol. No consistent effects on fetal or maternal androstenedione concentrations or on maternal estrogen levels were observed. Repeated short periods of increased fetal plasma ACTH concentration may promote maturation of the fetal adrenal, but there was no increase in androgen secretion by the gland nor was there an increase in estrogen production by the placenta under such conditions.