title: Perinatally administered bisphenol a as a potential mammary gland carcinogen in rats.
abstract: BACKGROUND
  Environmental exposure to bisphenol A (BPA) affects mammary gland development in rodents and primates. Prenatal exposure to environmentally relevant doses of BPA increased the number of intraductal hyperplasias and ductal carcinomas in situ by 50 days of age in Wistar-Furth rats.
  
  
  OBJECTIVE
  We aimed to determine whether BPA exposure of dams during gestation only or throughout lactation affects the incidence of mammary gland neoplasia in female offspring.
  
  
  METHODS
  We treated pregnant Sprague-Dawley rats with BPA at 0, 0.25, 2.5, 25, or 250 μg BPA/kg BW/day from gestational day (GD) 9 to birth and from GD9 to postnatal day (PND) 21. Mammary glands from BPA-exposed offspring were examined at four time points for preneoplastic and neoplastic lesions. To assess circulating BPA levels, we exposed pregnant rats to vehicle or 250 μg BPA/kg BW/day during gestation only or during gestation/lactation and analyzed sera from dams, fetuses, and nursing pups for total and unconjugated BPA.
  
  
  RESULTS
  Total and unconjugated BPA were detected in sera from 100% of dams and fetuses and 33% of pups exposed to 250 μg BPA/kg BW/day. Unconjugated BPA levels in exposed dams and fetuses (gestational) and in exposed dams and pups (gestational/lactational) were within levels found in humans. Preneoplastic lesions developed in BPA-exposed female offspring across all doses as early as PND50. Unexpectedly, mammary gland adenocarcinomas developed in BPA-exposed offspring by PND90.
  
  
  CONCLUSIONS
  Our findings suggest that developmental exposure to environmentally relevant levels of BPA during gestation and lactation induces mammary gland neoplasms in the absence of any additional carcinogenic treatment. Thus, BPA may act as a complete mammary gland carcinogen.
authors.affiliation: Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, MA 02111, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Acevedo
authors.forename: Barbara
authors.initials: B
authors.lastname: Davis
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Schaeberle
authors.forename: Carlos
authors.initials: C
authors.lastname: Sonnenschein
authors.forename: Ana M
authors.initials: AM
authors.lastname: Soto
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D002274:Carcinogens, Environmental / Q000008:administration & dosage / Q000633:toxicity*; D044584:Carcinoma, Ductal / Q000139:chemically induced*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006965:Hyperplasia / Q000139:chemically induced*; D015674:Mammary Neoplasms, Animal / Q000139:chemically induced*; D010636:Phenols / Q000008:administration & dosage / Q000097:blood / Q000633:toxicity*; D011247:Pregnancy; D051381:Rats; D011920:Rats, Inbred WF; D017207:Rats, Sprague-Dawley; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D002274:Carcinogens, Environmental; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds