Fig. 5. Effects of the subcutaneous administration of BD-1063 (16–64 mg/kg), S1RA (32–128 mg/kg), NE-100 (8–64 mg/kg), and saline (0) on the referred mechanical hyperalgesia induced by intracolonic administration of capsaicin 0.1% in WT and σ1-KO mice. The drug or saline was injected at 30 min before the capsaicin instillation. The referred mechanical hyperalgesia (evaluated by stimulation of the abdomen with von Frey filaments) was measured at 20 min after the capsaicin instillation. Each bar and vertical line represents the mean ± SEM of values obtained in 12 WT or 10 σ1-KO mice per group. The dashed and dotted lines indicate the 50% threshold in capsaicin solvent-treated WT and σ1-KO mice, respectively. Statistically significant differences between the values obtained in drug- and saline-injected mice: #P < 0.05; ##P < 0.01 (one-way ANOVA followed by Bonferroni test). WT, wild type; σ1-KO, σ1receptor knockout.