Fig. 2.

Effect of the neutralizing antibody against fractalkine (Ab FKN) in inflammatory hypernociception. The rats were pretreated (1 h) with Ab FKN (10 µg) or IgG control injected into the DRG (L5), followed by the injection of carrageenin (100 µg per paw) into the ipsilateral paw. At the indicated time points after carrageenin injection (A), mechanical hypernociception was evaluated, followed by the removal of the DRG (L5). (B) The expression of GFAP mRNA was determined. (C) Ab FKN (10 µg per DRG) or IgG control was also injected 1 h after carrageenin administration (100 µg per paw). Mechanical hypernociception was evaluated 3, 6, and 24 h after carrageenin injection. (D–F) The rats were pretreated (1 h) with Ab FKN (10 µg) or IgG control injected into the DRG (L5), followed by the injection of TNF-α (100 pg per paw), PGE₂ (100 ng per paw), or dopamine (10 µg per paw) into the ipsilateral paw. Mechanical hypernociception was evaluated 3 h after the injection of the inflammatory mediators. In all experiments, the data are expressed as the mean ± SEM of 10 animals per group. “*” indicates statistical significance compared with the saline injection (paw) group; “#” indicates statistical significance compared with the IgG control-treated group.