title: Morphometric evaluation of effects of two sex steroids on mammary gland of female rats.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of two sex hormones on normal mammary gland of female rats.
  
  
  METHODS
  Forty 250-day-old female rats, 20 of them with offspring and 20 not, were ovariectomized and, divided into 4 subgroups in order to receive one of the following subcutaneous treatment: estradiol benzoate (EB), medroxyprogesterone (MPA), EB+MPA or placebo, for 10 weeks. After treatment, mammary glands were studied with optical microscope. Whole gland, lobule, ductule and lumen compartments were evaluated by morphometric methods. Also a qualitative evaluation were performed seeking for secretion, microcalcification and trophic status.
  
  
  RESULTS
  It was found that (a) MPA-only and placebo were similar for all parameters; (b) the same between EB and EB+MPA; (c) EB and EB+MPA increased lobule, ductule and lumen compartments significantly compared to MPA-only or placebo; (d) EB increased epithelium but without significance and EB+MPA increased it significantly compared to placebo or MPA; (e) EB and EB+MPA incremented secretion.
  
  
  CONCLUSIONS
  In normal mammary gland of female rats: progestin action depends on estrogen presence. MPA does not revert estrogen-dependent proliferation, but it magnifies estradiol effect. Both EB and EB+MPA stimulate differentiation. Rats without offspring presented a greater epithelial proliferation under treatment with these sex hormones.
authors.affiliation: Department of Obstetrics and Gynecology, São Paulo University, Medicine School, São Paulo 04646001, Brazil. gindoclmp@hotmail.com
authors.forename: Luciano M
authors.initials: LM
authors.lastname: Pompei
authors.forename: Filomena M
authors.initials: FM
authors.lastname: Carvalho
authors.forename: Silvia C B C
authors.initials: SC
authors.lastname: Ortiz
authors.forename: Milena C
authors.initials: MC
authors.lastname: Motta
authors.forename: Robison J
authors.initials: RJ
authors.lastname: Cruz
authors.forename: Nilson R
authors.initials: NR
authors.lastname: Melo
mesh_terms: D000818:Animals; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000187:drug effects; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D016014:Linear Models; D008321:Mammary Glands, Animal / Q000187:drug effects* / Q000473:pathology; D008525:Medroxyprogesterone / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: C074283:estradiol 3-benzoate; D004958:Estradiol; D008525:Medroxyprogesterone