Fig. 1. Effect of a single intraperitoneal injection of vehicle, 25 mg/kg or 50 mg/kg minocycline, on postoperative mechanical hypersensitivity. Withdrawal threshold increased after the administration of minocycline when injected 24 h after paw incision (  A ) (  P = 0.001 by two-way ANOVA). The highest dose of minocycline, however, did not increase the withdrawal threshold when injected 72 h after paw incision (  B ). The hind paw withdrawal thresholds (g) are shown as mean ± SEM (n = 6–8 for each group). *  P < 0.05 as compared with vehicle-treated group by one-way ANOVA.