[Action of tamoxifen on the sex organs of guinea pigs]. / Deistvie tamoksifena na polovye organy morskikh svinok.

ABSTRACT

Long-term administration of tamoxifen (3-5 months) in a dose of 0.4 mg/kg to guinea-pigs with estrogen-induced benign uterine tumors had no toxic effects on the animals. Tamoxifen caused no noticeable changes in the ovarian mass, however, 40% of the guinea-pigs manifested ovulation suppression. Analysis of vaginal smears showed that most animals were in the stage of unestrus. Long-term administration of tamoxifen alone did not lead to the development of uterine polyps or tumors. Tamoxifen alone or combined with synestrol provoked a marked decrease in the level of free cytoplasmic estrogen and glucocorticoid receptors in the uterines of the guinea-pigs. In the course of long-term administration of tamoxifen alone, a tendency towards progesterone receptor decrease in the uterus was demonstrated.