Intrasplenic ovarian neoplasm formation: direct measurement of FSH LH estrogens and progestins.

Peripheral serum concentrations of follicle stimulating hormone (FSH) luteinizing hormone (LH) estrogens and progestins were measured during the development of intrasplenic ovarian neoplasms in castrate rats and in rats with an end-to-side portacaval shunt. 92% of the animals developed granulosa-theca cell tumors at the site of ovarian implantation in the absence of a portacaval shunt. The maximum diameter of ovarian implants was considerably less in animals with portacaval shunts than in those without. Animals without shunts showed significantly higher levels of FSH and LH (p. <.01). LH and FSH levels increased to castrate levels in rats without portacaval shunts that developed tumors while these levels decreased to normal levels in the shunt group. However shunt animals showed a significant increase in peripheral estrogen levels and a decrease in progestin levels (p. < .01). The results indicate that intrasplenic ovarian implants are stimulated to excessive growth by elevated levels of gonadotropins.