title: Evaluation of Ki-67 antigen expression in the vaginal epithelium of castrated female rats treated with raloxifene and tamoxifen: a comparative study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of raloxifene and tamoxifen on Ki-67 antigen expression in the vaginal epithelium of castrated rats.
  
  
  METHODS
  Thirty-nine virgin, adult, castrated female Wistar-Hannover rats were randomly divided into three groups: Group I (control, n = 13), Group II (raloxifene, n  = 13) and Group III (tamoxifen, n = 13). After confirmation of their hypoestrogenic state, the rats were given 0.5 ml of propylene glycol (vehicle), 750 μg of raloxifene or 250 μg of tamoxifen, respectively, by gavage, for 30 days. On the 31st day, the rats were euthanized and their vaginas removed and fixed in 10% buffered formalin for of Ki-67 immunohistochemical evaluation. Data were analyzed using Levene's test and Tukey's method (p < 0.05).
  
  
  RESULTS
  Mean Ki-67 expression in groups I, II and III was 27 ± 2.6, 32.3 ± 1.9 and 43.7 ± 3.5, respectively. In Group III (tamoxifen), there was a greater proportion of stained cells compared to Groups I and II (p < 0.0003), with no statistically significant difference between Groups I and II (p = 0.3626).
  
  
  CONCLUSIONS
  The present results show that tamoxifen significantly increased cell proliferation in the vaginal epithelium of the castrated rats and no difference between the raloxifene and control groups.
authors.affiliation: a Department of Gynecology , Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: Adinaide C
authors.initials: AC
authors.lastname: de Moura-Leal
authors.affiliation: b Veterinary Hospital, Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: João Macedo
authors.initials: JM
authors.lastname: de Sousa
authors.affiliation: a Department of Gynecology , Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: Heyder
authors.initials: H
authors.lastname: de Moura-Leal
authors.affiliation: a Department of Gynecology , Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: Gabriela V
authors.initials: GV
authors.lastname: de Sousa
authors.affiliation: c Department of Statistics , São Paulo University , São Paulo , Brazil , and.
authors.forename: Airlane P
authors.initials: AP
authors.lastname: Alencar
authors.affiliation: a Department of Gynecology , Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: Umbelina Soares
authors.initials: US
authors.lastname: Borges
authors.affiliation: d Genetics and Molecular Biology Laboratory, Federal University of Piauí , Teresina , Brazil.
authors.forename: Giovanny R
authors.initials: GR
authors.lastname: Pinto
authors.affiliation: a Department of Gynecology , Federal University of Piauí , Teresina, Piauí , Brazil .
authors.forename: Benedito B
authors.initials: BB
authors.lastname: da Silva
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects*; D005260:Female; D019394:Ki-67 Antigen / Q000187:drug effects*; D010052:Ovariectomy; D020849:Raloxifene Hydrochloride / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D020845:Selective Estrogen Receptor Modulators / Q000008:administration & dosage / Q000494:pharmacology*; D013629:Tamoxifen / Q000008:administration & dosage / Q000494:pharmacology*; D014621:Vagina / Q000187:drug effects*
chemical_list: D019394:Ki-67 Antigen; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen; D020849:Raloxifene Hydrochloride
keywords: Castrated female rat; SERMs; postmenopause; raloxifene; tamoxifen