Role of gonadotrophic hormone in the initiation and progression of adrenal tumors in ovariectomized mice.

Ovariectomy of (C57 X NH) F1 mice resulted in estrogen-secreting adrenal adenomas and estrous-type vaginal smears. Parabiosis with intact (C57 X NH) F1 females usually converted the vaginal smears from estrous to diestrous but produced a constant-estrous type smear in the intact parabiont. Ovariectomy of the latter resulted usually in restoration of an estrous-type smear in the tumorous animal and in its own smear's becoming diestrous. This is interpreted as indicating preferential action of the high gonadotrophic hormone levels of the tumorous animal on, or utilization by, the ovaries of the intact parabiont. The consequent diminution of estrogen output by the adrenal tumors is interpreted as evidence for an etiological role of the high postcastration gonadotrophic hormone levels in the induction of estrogen-secreting adrenal adenomas. Ovariectomy of strain CE mice resulted in estrogen-secreting adrenal adenoma formation within 6 months, with progression to adrenal carcinomas by 18 months. Progression was prevented by introduction of ovarian isografts at 6 months postcastration, indicating an etiologic role of the high postcastration levels of gonadotrophic hormone in the progression of adrenal adenomas to carcinomas.