Changes in Plasma ACTH and Corticosteroid of the Maternal and Fetal Sheep During Hypoxia

The changes occurring in the plasma concentrations of ACTH and corticosteroids of maternal and fetal sheep, with chronically implanted catheters before, during and after hypoxia have been measured. During hypoxia there was a transient rise in maternal plasma ACTH which was associated with a large rise in plasma corticosteroids. In contrastfetal plasma ACTH showed a large and prolonged rise during hypoxia with little change (except in one case) in plasma corticosteroid levels. In the fetus, therefore, the adrenalappears to be far less sensitive to ACTH stimulation than in the mother. There was no consistent correlation between the pCO2, pH and ACTH changes observed.(Endocrinology94: 588, 1974)