Figure 4

Changes of thermal hyperalgesia and NR2B expression by IL-8. (A) Compared with left paws of control, CFA-treated ipsilateral paws (left) showed a significant decrease in PWL; however, microinjection of repertaxin (0.5 μg/0.5 μl) into the ACC induced a significant increase in PWL in CFA-treated ipsilateral hind-paws. (B) Compared to right paws of control, CFA-treated contralateral paws (right) also showed a notably decrease in PWL, and microinjection of repertaxin (0.5 μg/0.5 μl) into the ACC induced a significant increase in PWL in CFA-treated contralateral hind-paws. n = 6 in each group. ** p < 0.01 compared with saline control; ^# p < 0.05 compared with CFA-injected alone. (C) Western blot analysis was performed using antibodies for NR2A, NR2B, and phosphorylated NR2B at Ser-1303 (p-Ser1303-NR2B). (D) There was no difference in NR2A expression among three groups. (E-F) NR2B and phosphorylated NR2B expressions in the ACC were notably increased at 3 d after CFA-injection; however, microinjection of repertaxin (0.5 μg/0.5 μl) into the ACC induced a significant decrease in NR2B or phosphorylated NR2B expression in CFA-injected mice. n = 6 in each group. * p < 0.05, ** p < 0.01 compared with control; ^# p < 0.05 compared with CFA-injected alone.