title: Effect of moderate ethanol consumption on mammary gland structural development and DNA synthesis in the female rat.
abstract: Epidemiological and experimental evidence provides support for a positive association between alcohol consumption and the development of breast cancer. To examine a mechanism for this association, young female Sprague-Dawley rats were pair-fed liquid diets containing ethanol at 0%, 15%, 20%, and 25% of calories for 32 days. The structural development and DNA-labeling index of the mammary gland were determined. Ethanol consumption at 20% and 25% of calories increased the density of carcinogen-sensitive terminal end bud (TEB) structures and decreased the density of carcinogen-insensitive alveolar bud structures of the developing mammary gland as compared to ad lib-fed and pair-fed controls. Consumption of ethanol at 20% and 25% of calories was also associated with a significant enhancement in the DNA-labeling index of mammary gland TEB structures, the target tissue for chemically-induced rat mammary tumorigenesis. In a separate study, serum progesterone but not estradiol, was decreased for rats fed ethanol at 25% of calories as compared to ad lib-fed and pair-fed controls. Thus moderate ethanol consumption at 20% and 25% of calories can delay the maturation and increase TEB DNA synthesis of the normal rat mammary gland. These changes may be explained by an ethanol-associated decrease in serum progesterone, a hormone important for the maturation of the mammary gland epithelium in the young female rat.
authors.affiliation: Division of Foods and Nutrition, University of Illinois, Urbana-Champaign 61801.
authors.forename: K W
authors.initials: KW
authors.lastname: Singletary
authors.forename: M Q
authors.initials: MQ
authors.lastname: McNary
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D002149:Energy Intake; D004958:Estradiol / Q000097:blood; D000431:Ethanol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D008099:Liver / Q000033:anatomy & histology; D008321:Mammary Glands, Animal / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development*; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000033:anatomy & histology; D011374:Progesterone / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000431:Ethanol; D011374:Progesterone; D004958:Estradiol; D004247:DNA