title: The timing of established detrusor hyperreflexia in a rat model of neuropathic bladder.
abstract: BACKGROUND
  Proper timing of catheter insertion and the use of a suitable surgical method are essential parts of producing rat models to evaluate neuropathic bladder following spinal cord injury (SCI).
  
  
  METHODS
  Thirty-two female Sprague-Dawley rats were randomly allocated into four groups. Group 1 underwent surgical laminectomy using the classic method. Group 2 underwent SCI 7 d following insertion of the catheter, and group 3 underwent sham operation. For bladder catheterization, a 4.5 Fr catheter was fixed into the bladder and tunneled beneath the skin to reach out at the nape of the neck. Group 4 underwent urodynamic study via bladder catheter prior to surgery and every 10 d following the operation to determine the exact time of establishing neuropathic bladder following spinal shock. The animals' survival rate and bladder wall's histopathologic changes were assessed 30 d following the operation.
  
  
  RESULTS
  Simultaneous suprapubic catheter placement raised the mortality rate in group 1 in comparison with group 2. Repeated urodynamic study in group 4 showed hypertonic behavior in the bladder 10 d after SCI, with significantly increased leak point pressure and bladder capacity; however, the end filling pressure and constant neuropathic bladder on cystometric indices are attained from 20 d after the operation.
  
  
  CONCLUSIONS
  Insertion of a bladder catheter 1 wk prior to SCI provides an applicable route for repeated cystometric studies in rats. The results demonstrate that sustained bladder overactivity is established in rats 20 d after SCI and animals are ready for further experiments on neuropathic bladder dysfunction following this period.
authors.affiliation: Pediatric Urology Research Center, Department of Pediatric Urology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran. kajbafzd@sina.tums.ac.ir
authors.forename: Abdol-Mohammad
authors.initials: AM
authors.lastname: Kajbafzadeh
authors.forename: Payam
authors.initials: P
authors.lastname: Mohammadinejad
authors.forename: Asal
authors.initials: A
authors.lastname: Hojjat
authors.forename: Behtash Ghazi
authors.initials: BG
authors.lastname: Nezami
authors.forename: Saman Shafat
authors.initials: SS
authors.lastname: Talab
authors.forename: Hamed
authors.initials: H
authors.lastname: Emami
authors.forename: Shadi Abdar
authors.initials: SA
authors.lastname: Esfahani
mesh_terms: D000818:Animals; D003559:Cystostomy / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D007796:Laminectomy / Q000379:methods; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013119:Spinal Cord Injuries / Q000401:mortality / Q000503:physiopathology*; D013997:Time Factors; D001750:Urinary Bladder, Neurogenic / Q000401:mortality / Q000503:physiopathology*; D053201:Urinary Bladder, Overactive / Q000401:mortality / Q000503:physiopathology*; D014546:Urinary Catheterization / Q000379:methods