title: Effects of neonatally administered diethylstilbestrol on induction of mammary carcinomas induced by 7, 12-dimethylbenz(a)anthracene in female rats.
abstract: Various doses of diethylstilbestrol (DES) were administered to rats once at birth. Thereafter, at 50 days after birth, the rats in all groups were given 10 mg 7, 12-dimethylbenz[a]anthracene (DMBA) and undergone necropsy at 300 days after birth. The incidence of mammary carcinomas (MCs) were 50, 54, 91, 39, 19% at 175 days after birth, and 77, 87, 100, 85, 75% at necropsy in the 0, 0.1, 1, 10, 100 microg groups, respectively. The incidence of rats without corpus luteum were 0, 0, 0, 30, 100% at 50 days after birth, and 0, 40, 53, 93, 100% at necropsy in the 0, 0.1, 1, 10, 100 microg groups, respectively. Observation of the whole mount specimens showed a higher number of terminal end buds (TEBs) in the 1 microg group and a lower number in the 100 microg group compared with the control at 50 days after birth. It suggested that the administration of a relatively low dose (1 microg) of DES during neonatal period may increase TEBs, thus resulting in a stimulatory effect on the initiation of MCs.
authors.affiliation: Department of Tumor Pathology, Field of Oncology, Kagoshima University, Kagoshima, Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kawaguchi
authors.forename: Masakazu
authors.initials: M
authors.lastname: Souda
authors.forename: Shuuhei
authors.initials: S
authors.lastname: Taguchi
authors.forename: Mamoru
authors.initials: M
authors.lastname: Funato
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Umekita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yoshida
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D000831:Animals, Newborn; D003338:Corpus Luteum / Q000002:abnormalities; D004054:Diethylstilbestrol / Q000633:toxicity*; D004971:Estrus / Q000187:drug effects; D005260:Female; D019394:Ki-67 Antigen / Q000032:analysis; D008321:Mammary Glands, Animal / Q000473:pathology; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019394:Ki-67 Antigen; D015127:9,10-Dimethyl-1,2-benzanthracene; D004054:Diethylstilbestrol