title: An animal study to compare the degree of the suppressive effects on the afferent pathways of micturition between tamsulosin and sildenafil.
abstract: BACKGROUND
  Tamsulosin, an α1-adrenoceptor antagonist, and sildenafil, a phosphodiesterase (PDE) inhibitor, are reported to improve lower urinary tract symptoms including overactive bladder (OAB). This study is aimed at investing the effects of tamsulosin and sildenafil and comparing the degree of the suppressive effects on the afferent pathways of micturition between them using an animal model of OAB, the spontaneously hypertensive rat (SHR).
  
  
  RESULTS
  The cystometric parameters, the basal pressure and duration of bladder contraction, were significantly increased in the SHR group as compared with the Wistar-Kyoto (WKY) group. The intercontraction interval also significantly decreased in the SHR group. In the SHR-Tam 0.01 mg/kg group and the SHR-Sil 1 mg/kg group, however, the basal pressure and duration were significantly reduced and the intercontraction interval was significantly prolonged. Moreover, the degree of the expression of c-Fos and NGF was significantly higher in the SHR group as compared with the WKY group. But it was significantly reduced in the SHR-Tam 0.01 mg/kg group and the SHR-Sil 1 mg/kg group. Furthermore, tamsulosin had a higher degree of effect as compared with sildenafil.
  
  
  CONCLUSIONS
  In conclusion, α1-adrenergic receptor antagonists and PDE-5 inhibitors may have an effect in improving the voiding functions through an inhibition of the neuronal activity in the afferent pathways of micturition.
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: Il-Gyu
authors.initials: IG
authors.lastname: Ko
authors.forename: Lakkyong
authors.initials: L
authors.lastname: Hwang
authors.forename: In-Young
authors.initials: IY
authors.lastname: Choi
authors.forename: Mal-Soon
authors.initials: MS
authors.lastname: Shin
authors.forename: Chang-Ju
authors.initials: CJ
authors.lastname: Kim
authors.affiliation: Department of Urology, Gil Medical Center, Gachon University, #1198 Guwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea. kimcho99@gilhospital.com.
authors.forename: Khae-Hawn
authors.initials: KH
authors.lastname: Kim
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology*; D000344:Afferent Pathways / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D005260:Female; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D011687:Purines / Q000494:pharmacology; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology*; D000077409:Tamsulosin; D014554:Urination / Q000187:drug effects*
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D013450:Sulfones; D000068677:Sildenafil Citrate; D000077409:Tamsulosin