Fig 5. H₂O₂-induced nociceptive behavior in rats as total time spent flinching, lifting and licking of the hind leg.

(A) Spontaneous nociceptive behavior after intramuscular (n = 6) or subcutaneous (n = 5) injection of H₂O₂ (100 mM, 0.6 ml), or intramuscular injection of synthetic interstitial fluid (0.6 ml) (n = 6). * P = 0.0004 compared with control group, † P = 0.0010 compared with subcutaneous H₂O₂ injection group by one-way ANOVA followed by post-hoc Bonferroni’s test. (B) Effects of local pre-injection of a TRPA1 antagonist (HC-030031; 50 mM, 0.3 ml, n = 6) on nociceptive behavior caused by intramuscular injection of H₂O₂ (100 mM, 0.3 ml, n = 7) vs. vehicle group (n = 7). * P < 0.0001 compared with vehicle + PBS injection group, † P < 0.0001 compared with HC-030031 + H₂O₂ injection group by one-way ANOVA followed by post-hoc Bonferroni’s test. All data are expressed as means ± SEM.