Figure 7

Effect of repeated MMP-2/9 inhibition on allodynia and hyperalgesia in naive rats. Repeated intra-plantar administration of MMP-2/9 inhibitor (MMP-2/9I.; 10, 20, 40 μg, i.pl.) once daily for fourteen days induced allodynia and hyperalgesia. Behavioral tests: the von Frey test (A), Hargreaves test (B) and acetone test (C) were performed on the 1st, 3rd, 7th and 14th day of repeated MMP-2/9 inhibitor injections. Results are presented as the mean ± SEM (n = 6–8 rats/group). Inter-group differences were analyzed by Bonferroni’s multiple comparison test. *p < 0.05, **p < 0.01, ***p < 0.001, compared to vehicle-treated (V) naïve rats. The area under the curve (AUC) was calculated by the Trapezoidal & Simpson’s Rules, Pharmacologic Calculation System, version 4.0-03/11/86. Inter-group differences were analyzed by Bonferroni’s Multiple Comparison Test. *p < 0.05, **p < 0.01, ***p < 0.001 indicate a significant difference as compared to chronic vehicle-treated (V) naive rats.