Fig. 3. Effects of the subcutaneous administration of BD-1063 (32 mg/kg) or saline on the referred mechanical hyperalgesia induced by intracolonic administration of different concentrations of capsaicin (0.01–1%) or its solvent (0) in WT (A ) and σ¹-KO (B ) mice. BD-1063 or saline was injected at 30 min before the administration of capsaicin or its solvent. The referred mechanical hyperalgesia (evaluated by stimulation of the abdomen with von Frey filaments) was measured at 20 min after instillation of capsaicin or its solvent. Each point  and vertical line  represents the mean ± SEM of values obtained in 12 WT or 10 σ¹-KO mice per group. Statistically significant differences compared to BD-1063–injected mice: *P < 0.05; **P < 0.01 (two-way ANOVA followed by Bonferroni test). WT, wild type; σ¹-KO, σ¹receptor knockout.