title: Morphological and functional response to injury to the external urethral sphincter - similarities and differences between male and female rats.
abstract: OBJECTIVE
  The objective of this study was to evaluate the similarities and differences of the urethral morphological and functional changes following external urethral sphincter EUS injury in male and female rats.
  
  
  METHODS
  30 female and 30 male age-matched Wistar rats were used in the experiments. Half of them underwent electrocauterization of the surrounding tissues lateral to the urethra at the level of the (EUS) and the others, a sham operation. At 2, 6, and 16 weeks after surgeries they underwent anesthetized cystometry, measurement of leak point pressure (LPP) and their urethras were harvested for morphological analyses.
  
  
  RESULTS
  There were no differences in cystometric parameters between sex-time-matched animals, ensuring normal bladder function in the manipulated animals. The mean LPP in male and female rats was lower compared with sham animals. Age-time-matched sham operated male rats exhibited a higher LPP compared with female rats. The reduction in LPP comparing electrocauterized and sham time-matched animals was more pronounced in male rats than in female rats. Electrocauterization produced urethral collagen deposition and nerve damage in both male and female animals. Muscle atrophy and disruption also occurred, being more evident in female rats.
  
  
  CONCLUSIONS
  The urethras of male and female rats exhibited a similar morphological and functional response to electrocauterization. The time-course evaluation revealed that the male animal model is as reliable, reproducible and long-lasting as the female model. Intact males had a higher LPP than female rats and the nerve injury led to a more drastic impairment of this mechanism.
authors.affiliation: Division of Urology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Scheila F C
authors.initials: SF
authors.lastname: Nascimento
authors.affiliation: Division of Urology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Ana Paula S
authors.initials: AP
authors.lastname: Bispo
authors.affiliation: Laboratory of Medical Investigation-LIM55, Urology Department, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: Katia Ramos
authors.initials: KR
authors.lastname: Leite
authors.affiliation: Department of Surgery, Division of Operative Technique and Experimental Surgery, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Helio
authors.initials: H
authors.lastname: Plapler
authors.affiliation: Department of Urology, University of Rostock, Rostock, Germany.
authors.forename: Claudius
authors.initials: C
authors.lastname: Füllhase
authors.affiliation: Division of Urology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Rogerio
authors.initials: R
authors.lastname: Simonetti
authors.affiliation: Division of Urology, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Soler
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D004564:Electrocoagulation; D005260:Female; D005355:Fibrosis; D008297:Male; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D009416:Nerve Regeneration; D059348:Peripheral Nerve Injuries / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D011312:Pressure; D017208:Rats, Wistar; D012737:Sex Factors; D013997:Time Factors; D014521:Urethra / Q000293:injuries* / Q000294:innervation / Q000378:metabolism / Q000503:physiopathology; D014550:Urinary Incontinence, Stress / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D014563:Urodynamics
chemical_list: D003094:Collagen
keywords: external urethral sphincter; leak point pressure; stress urinary incontinence; urodynamics