Effect of oral administration of oxybutynin on BVC and MP in conscious rats with bladder infused with different suramin concentrations. Data represent the mean (± S.E.) AUC change of BVC and MP calculated as reported in the Method Section. Oxybutynin was administered at 3 mg/kg (n = 8). Corresponding open bars represent changes recorded in the vehicle groups (n = 8). Suramin concentrations were 3 × 10-6 and 1 × 10-5 M. Rats were utilized 1 day after catheter implantation. Statistical significance was evaluated by Student's t test.