Gonadotropic Effect of Androgens upon the Immature Rat Ovary

Abstract

Butenandt and Kudzus 1 have reported that androgenic substances administered to immature female rats cause premature opening of the vagina. The present study was undertaken to determine whether the androgens produce this effect directly upon the genital tract or indirectly through the ovary.

Eighteen rats (comprising 5 litters), varying in age from 27 to 30 days, were used in this study. Twelve were given a single injection of androgen in sesame oil; 6 controls were given an equal quantity of pure sesame oil. Seven of the animals were injected with testosterone propionate and 5 with androstenediol,† the dosage varying from 1 to 5 mg.

The time of the opening of the vagina was noted in each case. Laparotomies were performed and one ovary removed at intervals varying from 60 to 96 hours after the administration of the androgen. The animals were sacrificed at periods varying from 96 to 228 hours after the injection and the remaining ovary was then removed. At corresponding intervals, the ovaries were removed from the control animals. The ovaries were examined microscopically in serial sections.

Opening of the vagina occurred in all androgen-injected animals within 72 hours after the injection. Follicle stimulation was noted as early as 60 and 72 hours after the injection. Corpora lutea were found as early as 96 hours and as late as 192 hours after androgen administration. The ovaries of all the 12 injected animals exhibited some gonadotropic effect, either follicle stimulation, luteinization or both. The uteri in all these animals were markedly enlarged. In the 6 control rats, the vaginas remained closed and the ovaries were negative.

Eighteen rats (comprising 5 litters), varying in age from 27 to 30 days, were used in this study. Twelve were given a single injection of androgen in sesame oil; 6 controls were given an equal quantity of pure sesame oil.