title: Morphometric analysis of the urethra of castrated female rats treated with tamoxifen.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of tamoxifen on the weight and thickness of the urethral epithelium of castrated female rats.
  
  
  METHODS
  Forty castrated adult female Wistar-Hannover rats were randomly divided into two groups: Group I (n=20) in which the animals received only the vehicle (propylene glycol) and Group II (n=20) in which the rats received tamoxifen 250microg/day by gavage. After 30 days of treatment, all animals were sacrificed and the urethra was immediately removed for weighing. Next, the urethra was divided into the proximal and distal segments, which were fixed in 10% formaldehyde and submitted to routine histological techniques for morphometric study. The data were analyzed using the weighted minimum mean-square error method and Student's t-test for two independent samples (p<0.05).
  
  
  RESULTS
  There was a significant increase in the mean weight of the urethra in the rats of Group II compared to the control group, 32.0+/-2.0mg and 22.0+/-1.6mg, respectively (p<0.001). The mean thickness of the distal urethral epithelium of the animals treated with tamoxifen was significantly greater than that of the control group, 42.8+/-2.0microm and 36.6+/-1.5microm, respectively (p<0.001). There was no statistically significant difference between the two groups with respect to the epithelial thickness of the proximal urethra (p=0.514).
  
  
  CONCLUSIONS
  Treating castrated adult rats with 250microg/day of tamoxifen for 30 days may increase the weight of the urethra and the thickness of the distal urethral epithelium.
authors.affiliation: Department of Gynecology, Federal University of Piauí, Teresina, Piauí, Brazil.
authors.forename: Alesse Ribeiro
authors.initials: AR
authors.lastname: dos Santos
authors.forename: Pedro Vitor
authors.initials: PV
authors.lastname: Lopes-Costa
authors.forename: Júlio César Dias
authors.initials: JC
authors.lastname: de Castro
authors.forename: Igor Cardoso
authors.initials: IC
authors.lastname: Campos
authors.forename: Rafael Soares
authors.initials: RS
authors.lastname: Borges
authors.forename: Cleicilene Gomes
authors.initials: CG
authors.lastname: Pires
authors.forename: Karina Oliveira
authors.initials: KO
authors.lastname: Drumond
authors.forename: Airlane Pereira
authors.initials: AP
authors.lastname: Alencar
authors.forename: Benedito Borges
authors.initials: BB
authors.lastname: da Silva
mesh_terms: D000818:Animals; D001284:Atrophy / Q000517:prevention & control; D004195:Disease Models, Animal; D005260:Female; D010052:Ovariectomy; D017698:Postmenopause / Q000502:physiology; D051381:Rats; D020845:Selective Estrogen Receptor Modulators / Q000494:pharmacology*; D013629:Tamoxifen / Q000494:pharmacology*; D014521:Urethra / Q000187:drug effects* / Q000473:pathology; D014549:Urinary Incontinence / Q000473:pathology / Q000517:prevention & control
chemical_list: D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen