Effects of different drugs on the cystometrogram in conscious rats

The effects on urodynamic parameters of i.v. administration of different drugs utilized in the therapy of detrusor instability, have been studied in conscious catheterized rats. Emepronium bromide, oxybutynin and nifedipine affected in a dose-dependent way the micturition pressure (MP), with sporadic changes in bladder volume capacity (BVC). Terodiline induced significant increases in BVC values in a wide range of doses. These changes, however, were always not dose-dependent. The drug significantly reduced MP only at the higher administered dose (10 mg/kg). Flavoxate induced increases of bladder capacity (BVC) not dependent on the administered doses, with no changes in micturition pressure (MP). Indomethacin significantly increased BVC and weakly reduced MP, but the effects were not dose-related. The effects of drugs on BVC were unrelated with the basal value of this parameter, whereas the decrease of MP seems to be related to high basal values before treatment. From a quantitative point of view, cystometrographic recordings in conscious normal rats can provide comparative data among drugs acting on bladder contractility (MP) such as anticholinergics and strong calcium antagonists.