4-Hydroxyandrostenedione is not an aromatase inhibitor in the neonatal guinea pig

One-day-old newborn guinea pigs were treated with 4-hydroxyandrostenedione (50 mg/kg body weight/day) for 5 or 12 consecutive days. This compound did not decrease unconjugated or sulfoconjugated estradiol and estrone levels in the plasma or in the uterine tissue itself. It also did not have any effect on uterine wet weight or the estrogen and progesterone receptor concentrations in the uterus. Moreover, progesterone receptor synthesis which is maintained when neonatal uteri are placed in organ culture conditions for 2 days was not affected by the 4-hydroxyandrostenedione treatment.