title: The prostate after castration and hormone replacement in a rat model: structural and ultrastructural analysis.
abstract: OBJECTIVE
  To evaluate if late hormonal replacement is able to recover the prostatic tissue modified by androgenic deprivation.
  
  
  METHODS
  24 rats were assigned into a Sham group; an androgen deficient group, submitted to bilateral orchiectomy (Orch); and a group submitted to bilateral orchiectomy followed by testosterone replacement therapy (Orch+T). After 60 days from surgery blood was collected for determination of testosterone levels and the ventral prostate was collected for quantitative and qualitative microscopic analysis. The acinar epithelium height, the number of mast cells per field, and the densities of collagen fibers and acinar lumen were analyzed by stereological methods under light microscopy. The muscle fibers and types of collagen fibers were qualitatively assessed by scanning electron microscopy and polarization microscopy.
  
  
  RESULTS
  Hormone depletion (in group Orch) and return to normal levels (in group Orch+T) were effective as verified by serum testosterone analysis. The androgen deprivation promoted several alterations in the prostate: the acinar epithelium height diminished from 16.58±0.47 to 11.48±0.29μm; the number of mast cells per field presented increased from 0.45±0.07 to 2.83±0.25; collagen fibers density increased from 5.83±0.92 to 24.70±1.56%; and acinar lumen density decreased from 36.78±2.14 to 16.47±1.31%. Smooth muscle was also increased in Orch animals, and type I collagen fibers became more predominant in these animals. With the exception of the densities of collagen fibers and acinar lumen, in animals receiving testosterone replacement therapy all parameters became statistically similar to Sham. Collagen fibers density became lower and acinar lumen density became higher in Orch+T animals, when compared to Sham. This is the first study to demonstrate a relation between mast cells and testosterone levels in the prostate. This cells have been implicated in prostatic cancer and benign hyperplasia, although its specific role is not understood.
  
  
  CONCLUSIONS
  Testosterone deprivation promotes major changes in the prostate of rats. The hormonal replacement therapy was effective in reversing these alterations.
authors.affiliation: Instituto de Ciências Humanas e da Saúde, Universidade Federal Fluminense, Rio das Ostras, RJ, Brasil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Felix-Patrício
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Alexandre F
authors.initials: AF
authors.lastname: Miranda
authors.affiliation: Fundação Educacional Dom André Arcoverde, Valença, RJ, Brasil.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Medeiros
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Carla B M
authors.initials: CBM
authors.lastname: Gallo
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Bianca M
authors.initials: BM
authors.lastname: Gregório
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Diogo B
authors.initials: DB
authors.lastname: Souza
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Waldemar S
authors.initials: WS
authors.lastname: Costa
authors.affiliation: Urogenital Research Unit, Universidade Estadual do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Francisco J B
authors.initials: FJB
authors.lastname: Sampaio
mesh_terms: D000728:Androgens / Q000172:deficiency*; D000818:Animals; D020249:Hormone Replacement Therapy; D008297:Male; D009919:Orchiectomy; D011467:Prostate / Q000187:drug effects / Q000473:pathology* / Q000648:ultrastructure*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood*
chemical_list: D000728:Androgens; D013739:Testosterone
keywords: Hormone Replacement Therapy; Hypogonadism; Prostate