title: Effects of soy on the mammary glands of premenopausal female monkeys.
abstract: OBJECTIVE
  To evaluate the interactive effects of dietary soy and menstrual cycle phase on breast proliferation, apoptosis, and sex steroid receptor expression in premenopausal female cynomolgus monkeys.
  
  
  METHODS
  Animals were randomized to receive diets with either casein lactalbumin or soy as the protein source for 12 months. Paired follicular and luteal mammary gland biopsies were taken before and after treatment and evaluated for epithelial proliferation and area, apoptosis, and sex steroid receptor expression.
  
  
  METHODS
  Academic research environment.
  
  
  METHODS
  Fifty-two adult female cynomolgus monkeys (Macaca fascicularis).
  
  
  METHODS
  Soy protein with the human equivalent of 129 mg/d of isoflavones.
  
  
  METHODS
  Breast proliferation and epithelial area.
  
  
  RESULTS
  Follicular and luteal assessments were taken on cycle day (+/- SE) 5.3 +/- 0.1 and 22.0 +/- 0.1, respectively. Serum E2, serum P, breast proliferation, and vaginal maturation were significantly higher in the luteal vs. follicular phase. Soy treatment resulted in significantly higher serum isoflavone concentrations compared with the casein lactalbumin group but did not significantly affect breast proliferation, epithelial area, apoptosis, or progesterone receptor expression; uterine size; or vaginal maturation in either the follicular or luteal phase.
  
  
  CONCLUSIONS
  Results indicate that dietary levels of soy intake have no detectable hormonal effects on the premenopausal breast.
authors.affiliation: Section on Comparative Medicine, The Comparative Medicine Clinical Research Center, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1040, USA. chwood@wfubmc.edu
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wood
authors.forename: Jay R
authors.initials: JR
authors.lastname: Kaplan
authors.forename: Petra
authors.initials: P
authors.lastname: Stute
authors.forename: J Mark
authors.initials: JM
authors.lastname: Cline
mesh_terms: D000284:Administration, Oral; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004785:Environmental Pollutants / Q000633:toxicity*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D008252:Macaca fascicularis; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000502:physiology*; D008597:Menstrual Cycle / Q000187:drug effects / Q000502:physiology*; D017697:Premenopause / Q000187:drug effects / Q000502:physiology*; D011980:Receptors, Progesterone / Q000378:metabolism*; D030262:Soybean Proteins / Q000008:administration & dosage*; D014018:Tissue Distribution
chemical_list: D004785:Environmental Pollutants; D012739:Gonadal Steroid Hormones; D011980:Receptors, Progesterone; D030262:Soybean Proteins