title: Impact of tamsulosin and nifedipine on contractility of pregnant rat ureters in vitro.
abstract: OBJECTIVE
  To evaluate the in vitro effect of tamsulosin and nifedipine on the contractility of pregnant rat ureters and to perform quantitative analysis of the pharmacological effects. Medical expulsive therapy (MET) is commonly used to treat urolithiasis. However, this treatment is seldom used in pregnant women since no studies support this practice.
  
  
  METHODS
  This was an in vitro study on animal tissue derived from pregnant Sprague-Dawley rats. A total of 124 ureteral segments were mounted in an organ bath system and contractile response to methacholine (MCh) was assessed. Tamsulosin or nifedipine were added at cumulative concentrations (0.001-1 μM). The area under the curve (AUC) from isometric tension measurements was calculated. The effect of pharmacological agents and the respective controls were assessed by calculating the AUC for each 5-min interval. Statistical analyses were performed using the Mann-Whitney-Wilcoxon nonparametric test.
  
  
  RESULTS
  Both drugs displayed statistically significant inhibitory activity at concentrations of 0.1 and 1 μM for tamsulosin and 1 μM for nifedipine when calculated as the AUC as compared to DMSO controls.
  
  
  CONCLUSIONS
  Tamsulosin and nifedipine directly inhibit MCh-induced contractility of pregnant rat ureters. Further work is needed to determine the clinical efficacy of these medications for MET in pregnancy.
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Lisette
authors.initials: L
authors.lastname: Haddad
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Corriveau
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Rousseau
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Blouin
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Pasquier
authors.affiliation: b Department of Surgery , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Ponsot
authors.affiliation: a Department of Obstetrics and Gynecology , Urology Division, Centre Hospitalier Universitaire de Sherbrooke , Sherbrooke , Québec , Canada.
authors.forename: Marie-Ève
authors.initials: MÈ
authors.lastname: Roy-Lacroix
mesh_terms: D000818:Animals; D005260:Female; D007669:Kidney Calculi; D016210:Methacholine Chloride / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013449:Sulfonamides / Q000494:pharmacology*; D000077409:Tamsulosin; D014513:Ureter / Q000187:drug effects* / Q000502:physiology
chemical_list: D013449:Sulfonamides; D016210:Methacholine Chloride; D000077409:Tamsulosin; D009543:Nifedipine
keywords: Medical expulsive therapy; nifedipine; pregnancy; tamsulosin; ureters; urolithiasis