Inhibition of cathepsin G attenuated complete Freud’s adjuvant (CFA)–induced heat hyperalgesia in rats. (A) Pretreatment with subcutaneous injection of cathepsin G inhibitor tosyl phenylalanyl chloromethyl ketone (TPCK) attenuated CFA-induced heat hyperalgesia compared with controls using dimethyl sulfoxide as vehicle, n = 12, P < 0.0001, repeated-measures ANOVA. (B) Postadministration of TPCK on day 4 after intraplantar CFA injection reversed heat hyperalgesia, n = 14, P < 0.05, repeated-measures ANOVA. *P < 0.05, **P < 0.01, ***P < 0.001, Bonferroni-adjusted t test. Error bars represent SEM.