Development of Adrenal Cortical Adenomas is Ovariectomized Mice Injected with “Physiologic” Doses of Sex Hormone. ∗

Since the development of adrenal cortical adenomas in gonadectomized mice has been inhibited by the implantation of pellets of estrogenic hormone, 1 it might be inferred that withdrawal of gonadal secretion is of primary importance in precipitating the development of the castration-induced adenoma of the mouse adrenal cortex. The objective of the experiments being reported was to determine the effect of the administration of regulated, “physiologic” amounts of estrogenic or androgenic hormone on the induction of adrenal cortical tumors in susceptible ovariectomized mice.

Mice of the NH strain were used in these experiments. NH females develop adrenal cortical tumors spontaneously following ovarian regression, and precociously if gonadectomized. 2 Adrenal cortical adenomas are present in most NH mice of both sexes 5 months after removal of the gonads.

Four NH males and one female whihc had been gonadectomized at 23 days of age received (by subcutaneous injection beginning 2 weeks after operation) 0.05 microgram of estradiol dipropionate‡ in sesame oil at intervals of from 5 to 9 days. This treatment with estrogenic hormone provided for constant estrus, as determined by vaginal smear. These 5 animals were autopsied 6 months after the institution of hormone treatment. Administration of hormone was suspended 53 days before autopsy in 2 NH females which received similar treatment.

Two ovariectomized NH females received the same treatment with the estrogen and in addition were injected weekly with 150 μg of progesterone in oil. Two additional ovariectomized females received the estrogen plus progesterone, but treatment was suspended 47 days before autopsy.

Two NH females ovariectomized at 21 days of age were given 17.5 μg of testosterone propionate in oil weekly by subcutaneous injection beginning 2 weeks after operation. This treatment was continued until the animals were autopsied 5 1/2 months after ovariectomy. Three mice were similarly treated except that they received no injections of hormone for the 46 days preceding autopsy.