Effect of NOV treatment of sham and CFA rats on MMP-2/-9 expression and mechanical allodynia. NOV (3 μg/rat) was administrated daily by a single intrathecal injection (i.t) for 4 consecutive days starting from the 9th day after CFA injection. (A, B) Levels of MMP-2 and MMP-9 mRNA in the DRG (A) and DHSC (B) following intrathecal (i.t) treatment with NOV protein or vehicle (*P < 0.05 NOV- versus saline-treated CFA rats, n = 4 to 5). (C) Representative gelatin zymograph showing MMP-9 and MMP-2 activities (left panels) and quantification of MMP-2 and MMP-9 gelatinolytic bands (right panels). Data represent the mean ± SEM of three to four rats per group (*P < 0.05 NOV- versus saline-treated CFA rats). (D) The paw withdrawal threshold (g) was evaluated using the von Frey test. Data represent the mean ± SEM of eight rats per group (*P < 0.05, **P < 0.01 CFA/NOV- versus CFA/saline-treated rats).