Figure 4

Percutaneous RTX produces long-lasting, reversible inflammatory heat hyperalgesic inhibition (A) in a dose-dependent fashion (B). Inflammatory heat hyperalgesia is significantly inhibited 1 day (N = 8), 1 week (N = 6), and 2 weeks (N = 5) following application of RTX (250 ng, 50 μl) to the sciatic nerve (*P < 0.05, 1 way ANOVA). An intermediate response was seen at 1 month (N = 8), and at 3 months (N = 8). Complete recovery with a normal heat withdrawal response following inflammation was observed 6 months (N = 11) following treatment, indicating that the effect of RTX had reversed. The dose-response results (B) indicate that ≥ 125 ng is necessary for a significant anti-inflammatory effect, as compared to Pre-Inflammation values and to vehicle (P < 0.05). Note that the Pre-inflammation testing point represents the same testing day that the animal was to be inflamed. There was no difference between groups treated with RTX (N = 46); therefore data were pooled for the baseline (Baseline) and Pre-inflammation testing sessions. Animals treated with vehicle (N = 16) were also pooled in the Baseline, Pre-inflammation, and Post-inflammation groups for comparison.