Aromatase Inhibitors III. Studies on the Antifertility Effect of 4-Acetoxy-4-androstene-3,17-dione1, 2, 3

Abstract
4-Acetoxy-4-androstene-3,17-dione (4-acetoxy-A) was demonstrated to be an effective aromatase (estrogen synthetase) inhibitor in vitro. To study the effect of the compound on estrogen-dependent processes, rats were treated with silastic wafers containing 4-acetoxy-A (75 mg). These were inserted under the skin on Day 1 of diestrus. When housed continuously with male rats from the expected day of proestrus, 7/8 rats did not mate after 6-15 days of cohabitation.