Fig. 2.
Effects of nociceptor-selective block on mechanical hypersensitivity after plantar incision in rats. Rats were administered two perisciatic injections of 2% lidocaine and 0.2% QX-314 in combination with 0.05% capsaicin before and 12 h after plantar incision (n = 12) or sham procedures (n = 6). Additional control rats received perisciatic injections of 2% lidocaine/0.2% QX-314 alone (n = 6); 0.05% capsaicin alone (n = 6); or vehicle solutions (n = 12). Mechanical responses to von Frey filaments were measured in rats for several hours postincision (A). * P < 0.05/5 (0.01) versus preincision baseline values. # P < 0.05 compared with vehicle-injected rats. A subset of rats was monitored long term to determine effects of nociceptor-selective block on resolution of mechanical hypersensitivity over several days (B). Data are presented as mean ± SD. n = 6–12 rats per group in (A) and n = 3 per group in (B). * P< 0.05/6 (0.008) versus preincision baseline values. # P < 0.05 compared with vehicle-injected rats. cap = capsaicin; lid = lidocaine.