Effects of remifentanil on PWMT during the postoperative period and the intervention of ketamine. Ketamine (10 mg/kg, 0.1 ml) or saline was subcutaneously injected 30 min before surgery. Under sevoflurane anesthesia, remifentanil (0.04 mg/kg, 0.4 ml) or saline was subcutaneously infused in the absence or presence of the right hind paw incision during a period of 30 min. PWMT was evaluated at 24 h before incision and at 2 h, 6 h, 24 h and 48 h after surgery. Number of rats per group was twelve. Data are expressed as means ± SD. *P < 0.01 vs baseline, # P < 0.01 vs group C, ▽
P < 0.01 vs group I, △
P < 0.01 vs group R.