DMBA-induced uterine vascular tumors in BALB/c mice: ovary-dependent carcinogenic response.

Female BALB/c mice treated with a single intraperitoneal injection of 1 mg of 7, 12-dimethylbenz(a)anthracene (DMBA) at 4, 8 and 20 weeks of age showed a high incidence of uterine vascular tumors. Bilateral ovariectomy preceding DMBA treatment almost completely inhibited the induction of vascular tumors, while ovariectomy following DMBA treatment resulted in endometrial gland atrophy and a high incidence of vascular tumors. Vascular tumors were also induced when DMBA was given to neonatal androgenized mice, whereas among neonatal androgenized and normal female mice not treated with DMBA the incidence was 0%. Histological examinations revealed benign hemangiomas or angiosarcomas. In contrast, DMBA-treated male BALB/c mice and orchiectomized mice, and DMBA-untreated males showed no vascular tumors. A striking ovarian dependence of induction of uterine vascular tumors was observed.