CLP257 blocks and reverses hyperalgesic priming in both male and female mice. A, Animals received an intrathecal injection of 130 μmol CLP257 immediately before an intraplantar injection of 0.1 ng of IL-6. After initial mechanical hypersensitivity to IL-6 had resolved, mice received an intraplantar injection of 100 ng of PGE₂ (n = 4 mice/group). B, An intraplantar injection of 0.1 ng of IL-6 was given to animals and immediately before the intraplantar injection of 100 ng of PGE₂ injection animals received an intrathecal injection of 130 μmol CLP257 (n = 4 mice/group). Differences between groups were measured using a two-way ANOVA with Bonferroni's post hoc test: *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.