title: [Ultrasonographic histological study on the evolution of a canine model of hormone-induced benign prostatic hyperplasia].
abstract: BACKGROUND
  Despite exhibiting histological differences from the human process, canine hormone-induced benign prostatic hyperplasia (BPH) is still the most widely used animal model for evaluating treatment strategies.
  
  
  OBJECTIVE
  The aim of this study is to determine the optimal moment for starting a therapeutic trial in this animal model.
  
  
  METHODS
  Six male beagle dogs over one year of age were used in this study. All animals received a combination of steroid hormones, namely 17beta-estradiol and 5alpha-androstene 3alpha 17beta-diol, every other day during three (Group 1, n=3) or five months (Group 2, n=3). Transrectal ultrasonographic examinations to measure prostate volume were performed monthly. Animals were euthanized after five months for histological study of their prostates.
  
  
  RESULTS
  All animals developed BPH, with prostate volume increasing over time as hormones were administered (r=0,910). All ultrasonographic studies performed up to the third month evidenced a significant increase in prostate volume when compared to the prior ultrasound measurement. A significant decrease in prostate volume was seen in Group 1 once hormone administration was interrupted, whereas Group 2 animals showed a continuing increase in prostate size. Histological examination showed almost no evidence of BPH in Group 1 animals, while Group 2 animals clearly exhibited moderate epithelial hyperplasia.
  
  
  CONCLUSIONS
  The administration of a combination of steroid hormones is effective in inducing benign prostatic hyperplasia in canines, but this hyperplasia disappears when hormone treatment is interrupted. In order to be useful for experimental studies, hormones should be administered for at least three months before commencing any treatment, and they should be continued throughout the length of the study..
authors.affiliation: Centro de Cirugía de Mínima Invasión Jesús Usón, Cáceres, España. crisosto@ccmijesususon.com
authors.forename: Verónica
authors.initials: V
authors.lastname: Crisóstomo Ayala
authors.forename: Manuel
authors.initials: M
authors.lastname: Maynar Moliner
authors.forename: Fei
authors.initials: F
authors.lastname: Sun
authors.forename: Jesús
authors.initials: J
authors.lastname: Usón Gargallo
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Sánchez Margallo
mesh_terms: D000731:Androstanes / Q000008:administration & dosage; D000818:Animals; D004285:Dogs; D004958:Estradiol / Q000008:administration & dosage; D004967:Estrogens / Q000008:administration & dosage; D008297:Male; D011470:Prostatic Hyperplasia / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology*; D014463:Ultrasonography
chemical_list: D000731:Androstanes; D004967:Estrogens; D004958:Estradiol; C033936:androstane