Placental-ovarian relationship in the control of testosterone secretion in the rat

Both ovaries and placentae of rats produce androgen in the second half of pregnancy. The objectives of this investigation were to determine whether the pituitary controls both ovarian and placental secretion of testosterone, to find out whether ovarian secretion of testosterone is maintained by the placenta, and to examine whether levels of testosterone produced by the ovaries and placentae depend upon the number of placentae present. Pregnant rats were hypophysectomized with or without hysterectomy in one experiment, and hypophysectomized with or without partial hysterectomy leaving one placenta in situ in another experiment. Testosterone output by the placenta(e) or the ovary was quantified. The results suggest that placental secretion of testosterone is independent of the pituitary between days 12 and 18 of pregnancy, reduction in placental number causes the remaining placenta to compensate by increasing its testosterone output, and ovarian secretion of testosterone may be under placental control between days 12 and 18 of pregnancy.