CFA induces CXCR2/ERK dependent COX-2 increase in the spinal cord. (A) Intrathecal pretreatment with SB225002 or PD98059 partly prevented CFA-induced heat hyperalgesia. *** P < 0.001 compared to vehicle. Student's t-test. n=6 mice/group. (B) Intrathecal pretreatment with SB225002 or PD98059 decreased CFA-induced COX-2 mRNA increase in the spinal cord. *** P < 0.001 compared to naive. # P < 0.01, compared to vehicle. n=6 mice/group. (C) Intrathecal pretreatment with SB225002 or PD98059 reduced CFA-induced COX-2 protein expression and pERK1/2 activation in the spinal cord. (D, E) Density of COX-2 bands (D) and pERK1, pERK2 bands (E), which is normalized to GAPDH loading control. *** P < 0.001 compared to naive. ## P < 0.01, ### P < 0.001 compared to vehicle. One-way ANOVA followed by Newman-Keuls post hoc test. n = 4 mice/group.