Fig. 2. Effect of ketamine administered intravenously on reflex responses to urinary bladder distension (UBD). Time dependent effects on: (A ) change in mean arterial blood pressure (ΔMAP) and, (B ) abdominal electromyographic (EMG) activity evoked by UBD (60 mmHg, 20 s, every 4 min) after treatment with single boluses of ketamine 1 (n = 4), 3 (n = 6), 10 mg/kg (n = 5) or normal saline (n = 6). (C ) and (D ): effect of same doses of ketamine or saline on ΔMAP and EMG responses to graded UBD respectively. Data are presented as percentage of baseline responses and expressed as mean ± SEM. #P < 0.01, two-way repeated measures analysis of variance test followed by post hoc  analysis with Tukey–Kramer procedure.