Isometric force transducer

After 8 weeks of intervention, the rats (n = 8 per group) were anesthetized with sodium pentobarbital (40 mg/kg, intraperitoneal). A polyethylene tube (PE-50, Clay Adams, New Jersey, USA) was inserted into the bladder through the urethra and connected to a pressure transducer (Harvard Apparatus, Massachusetts, USA) and a microinjection pump (PHD 22/2000 Syringe Pump, Harvard Apparatus, Massachusetts, USA) via a 3-way stopcock, to record the bladder pressure and infuse the bladder with normal saline. The micturition volume was recorded by a liquid collector (Isometric Force Transducer, Harvard Apparatus, Massachusetts, USA). Saline was infused into the bladder at a rate of 0.6 ml/min. The urodynamic parameters of each group, such as volume threshold for eliciting micturition, maximum intravesical pressure (Pv, max), BC, voided volume, postvoid residual (PVR) volume, and V% (100 × PVR/BC), were calculated and compared. Measurements in each rat represented the average of five micturition cycles after an initial 45 min stabilization period.

ASM-024 was provided by Asmacure Ltée. ASM-024, methacholine (Methapharm Inc.) and salbutamol (Ventolin, GlaxoSmithKline) were solubilized in appropriate aqueous solution. Formoterol (LKT Laboratories Inc.) and salmeterol (Tocris) were diluted in DMSO. Tissues and cells were exposed to 0.1 to 0.5% DMSO. Isometric tensions were acquired with the data acquisition System MP150 (Biopac Systems) via an isometric force transducer (Harvard apparatus). The data were digitalized and analyzed with AcqKnowledge 3.7.3 software.
This study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the Canadian Council on Animal Care (CCAC) regarding acclimation, environmental enrichment, and analgesic and anesthesia procedures. The protocols were approved by the Committee on the Ethics of Animal Experiments of Université Laval. In two experiments, tissues from human donors were obtained after written informed consent in accordance with an Internal Review Board-approved protocol at IUCPQ Research Center (Institut universitaire de cardiologie et de pneumologie de Québec) in Québec, QC (Canada).