Abstract
Granulosa cell tumors/luteomas of the ovary were induced at very high incidence in the offspring of F344 rats receiving N-nitrosobis (2-oxopropyl) amine (BOP) transplacentally (Jpn. J. Cancer Res., 81: 1077-1080, 1990). In addition to ovarian tumors, atrophic and hyperplastic lesions were also frequently observed in the ovary and uterus of BOP-treated animals, respectively. In order to investigate the relation between granulosa cell tumors and uterine endometrial lesions, the lesions in BOP-treated rats with ovarian tumors were compared to those in the rats without tumors. While no endometrial adenocarcinoma was found in both rat groups, the incidence and degree of atypical, and adenomatous endometrial hyperplasias were slightly high in rats with ovarian tumors, as compared to rats without tumors, while being not significant. In the assay of plasma gonad steroids, hormonal imbalance was clearly detected in BOP-treated animals and the 17β-estradiol: progesterone (E2: P) ratio was higher in BOP-treated rats with ovarian tumors than control rats or treated rats without tumors. These results suggest that a slight association between ovarian tumors and endometrial proliferative lesions exists in rats and hormonal imbalance, particularly an increased E2: P ratio, might play an important role in the association.
