title: Effects of bladder function by early tamsulosin treatment in a spinal cord injury rat model.
abstract: OBJECTIVE
  To investigate the effects of early tamsulosin treatment on changes in bladder characteristics after a spinal cord injury.
  
  
  METHODS
  We divided 45 rats into three groups: the control (CON) group, the spinal cord injury (SCI) group, and the SCI+tamsulosin treatment (SCI+TAM) group. Spinal cord transection was performed in the SCI and SCI+TAM groups. Tamsulosin was injected for 7 days in the SCI+TAM group. Intravesical and intra-abdominal catheters were implanted before cord injury. Basal pressure (BP), maximal vesical pressure (MVP), micturition volume (MV), and voiding interval time (VIT) were measured at 7 days after SCI. The bladder was then removed and used for an in vitro organ bath study and Western blot analysis. The percentage changes in contractility from baseline after acetylcholine alone, pretreatment with a muscarinic 2 (M2) receptor blocker (AQ-RA741), and pretreatment with a M3 receptor blocker (4-DAMP) were compared among the groups. Western blot analyses were performed to determine expression levels of pERK1/2 and rho-kinase.
  
  
  RESULTS
  In cystometry, MVP, BP, MV, and VIT showed changes in the SCI and SCI+TAM groups versus the CON group (p<0.05). In the organ bath study, acetylcholine-induced contractility in the three groups differed significantly (p<0.05). Additionally, acetylcholine-induced contractility with 4-DAMP pretreatment was reduced significantly in the SCI+TAM group versus the SCI group. In Western blotting, pERK1/2 expression was stronger (p<0.05) and rho-kinase expression was weaker in the SCI+TAM group than the SCI group (p<0.05).
  
  
  CONCLUSIONS
  These results suggest that the bladder contraction due to acetylcholine after SCI can be decreased by tamsulosin in the acute stage and this involves changes in pERK1/2 and rho-kinase.
authors.affiliation: Department of Rehabilitation Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Korea.
authors.forename: Kang Keun
authors.initials: KK
authors.lastname: Lee
authors.affiliation: Department of Physiology, Wonkwang University School of Medicine, Iksan, Korea.
authors.forename: Moon Young
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Department of Urology, Wonkwang University School of Medicine, Iksan, Korea.
authors.forename: Dong Yeop
authors.initials: DY
authors.lastname: Han
authors.affiliation: Department of Urology, Wonkwang University School of Medicine, Iksan, Korea.
authors.forename: Hee Jong
authors.initials: HJ
authors.lastname: Jung
authors.affiliation: Department of Rehabilitation Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Korea.
authors.forename: Min Cheol
authors.initials: MC
authors.lastname: Joo
keywords: Neurogenic urinary bladder; Spinal cord injuries; Tamsulosin