title: The development and regression of deciduosarcomas and other lesions caused by estrogens and progestins in rabbits.
abstract: A series of experiments were conducted to study the histopathological effects of a combination of exogenous estrogens and progestins in mature rabbits. Estradiol (14-45 microg/day) and levonorgestrel (30-233 microg/day) were administered by intravaginal or subdermal Silastic devices for various time intervals to study the development of lesions with time and to determine if lesions regressed following withdrawal of the steroids. The origin of splenic decidual tumors (primary or metastasis from the uterus) was determined by administering the same steroid combination to castrated male rabbits. It was determined that uterine decidualization is present after 7 days of steroid treatment and that neoplasms of decidual cells may appear in the uterus after only 30 days of steroid administration. Decidual changes were observed frequently in uterine arteries, often concurrent with infarct-like areas of necrosis of the uterine wall. Withdrawal of contraceptive steroids for 14-120 days after 60 days' administration resulted in atrophy and disappearance of decidual cells and decidual tumors. Decidual neoplasms developed in the spleen of all castrated male rabbits given subdermal steroids, demonstrating that these tumors can arise as primary neoplasms of the spleen. The foregoing lesions appear to be peculiar to the rabbit and, together with previous data, suggest the rabbit to be a poor model for evaluating the effects of contraceptive steroids in other species.
authors.affiliation: Department of Pathology, The George Washington University Medical Center, Washington, DC 20037, USA. resbcz@gwumc.edu
authors.forename: B C
authors.initials: BC
authors.lastname: Zook
authors.forename: O A
authors.initials: OA
authors.lastname: Jänne
authors.forename: A A
authors.initials: AA
authors.lastname: Abraham
authors.forename: H A
authors.initials: HA
authors.lastname: Nash
mesh_terms: D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000473:pathology; D002822:Choriocarcinoma / Q000097:blood / Q000139:chemically induced / Q000473:pathology*; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000633:toxicity; D003656:Decidua / Q000187:drug effects / Q000473:pathology; D004338:Drug Combinations; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D016912:Levonorgestrel / Q000008:administration & dosage / Q000633:toxicity*; D008297:Male; D009336:Necrosis; D009365:Neoplasm Regression, Spontaneous; D009919:Orchiectomy; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000633:toxicity*; D011817:Rabbits; D012741:Sexual Maturation; D012826:Silicone Elastomers / Q000008:administration & dosage; D013045:Species Specificity; D013154:Spleen / Q000473:pathology; D013160:Splenic Neoplasms / Q000139:chemically induced / Q000473:pathology*; D013997:Time Factors; D014594:Uterine Neoplasms / Q000097:blood / Q000139:chemically induced / Q000473:pathology*; D014599:Uterus / Q000098:blood supply / Q000187:drug effects / Q000473:pathology
chemical_list: D003271:Contraceptive Agents, Female; D004338:Drug Combinations; D004343:Drug Implants; D045167:Progesterone Congeners; D012826:Silicone Elastomers; D004958:Estradiol; D016912:Levonorgestrel