Fetal-maternal gradients of steroid hormones in the nine-banded armadillo (Dasypus novemcinctus)

Abstract

Gonadal and adrenal steroid hormone levels in plasma were measured in pregnant, non-pregnant and fetal armadillos. Progesterone demonstrated the largest placental gradient with levels 6 to 10-fold higher in the fetus. Testosterone levels were higher in male and lower in female fetuses, when compared to the respective maternal serum values. Dehydroepiandrosterone, and cortisol were consistently high in maternal as compared to matched fetal serum samples whereas the reverse was true for androstenedione. Tissue incubations with labelled pregnenolone indicated the major source of progesterone production to be the fetal adrenal whereas the fetal testes demonstrated a major conversion product consistent with dehydroepiandrosterone.