Figure 4
IL-1β maturation, but not maturation of IL-18, is involved in caspase-1 mediation of inflammatory hypernociception. (A) Wild type or IL-18-/- mice received an intraplantar injection of carrageenin (100 μg/paw). Mechanical hypernociception was evaluated 3 h after carrageenin injection. Mice were pretreated with IL-1ra (3-90 mg/kg, i.v. 15 min before carrageenin injection) followed by intraplantar injection of carrageenin (100 μg/paw). Mechanical hypernociception was evaluated 3 h after carrageenin injection. (C) After the determination of hypernociception, mice paw skins were removed and the activity of MPO was determined. (D) Wild type and casp1-/- mice received an intraplantar injection of carrageenin or saline. After 1.5 h, plantar tissue samples were removed and the level of pro-IL-1β mRNA was determined by real-time PCR. (D) Wild type and casp1-/- mice received an intraplantar injection of carrageenin or saline. After 3 h, plantar tissue samples were removed and the level of mature IL-1β (~19 kDa) was determined by western blot. The β-actin level was used as a control. Data are presented as representative blots. Densitometry of the pixel intensity of IL-1β bands relative to β-actin is present. Data are expressed as the mean ± S.E.M. of 5 animals per group. * indicates statistical significance compared to the saline-injected group; # indicates statistical significance compared to the vehicle-treated group or wild type mice group. P < 0.05, one-way ANOVA followed by the Bonferroni's test.