Effects of the interaction of the ovary with an androstane nitrile on the uterus of the rat.

The compound 17 cyano-5,16 androstadien-3 beta-ol-acetate (cyanoacetate) was considered as a promising candidate for use as a contraceptive agent, since it was reported to specifically inhibit the ovarian conversion of pregnenolone to progesterone. A preliminary study in rats indicated that this compound had unique properties that interfered with the interpretation of results concerning the decidual response. It appeared to interact with the ovaries of the animal to cause an increase in uterine weight. Because of these observations, a multiple factorial study was designed to determine whether this compound was, in fact, more uterotrophic in intact, than in spayed, psuedopregnant rats. The study demonstrated that the presence of the ovary resulted in a significantly greater uterine weight, while 2 mg progesterone daily for 10 days had no significant effect on uterine weight. Cyanoacetate (10 mg/day for 10 days) was found to increase uterine weight significantly in intact, but not spayed, psuedopregnant rats. Neither cyanoacetate (10 mg/day) nor progesterone (2 mg/day) affected ovarian weight. The data suggest that cyanoacetate is converted by the ovary from a compound with little uterotrophic activity to a material with substantial uterotrophic activity.