Figure 4.

GsMTx-4 reverses paclitaxel chemotherapy-induced mechanical hyperalgesia. Rats treated with paclitaxel (daily for 10 d) develop mechanical hyperalgesia (118 ± 2 g, n = 12 before and 74 ± 3 g, n = 6 after paclitaxel; p < 0.001, Tukey's post hoc multiple comparison test). Intradermal injection of GsMTx-4 in the hindpaw 30 min before mechanical nociceptive threshold testing reversed the mechanical hyperalgesia (74 ± 3 g before GsMTx-4 and 116 ± 2 g after; n = 6; p < 0.001, Tukey's post hoc multiple comparison test). Twenty-four hours after the administration of GsMTx-4, mechanical nociceptive thresholds were not significantly different from pre-GsMTx-4 paw-withdrawal thresholds (n = 6 for each group; p > 0.05, Tukey's post hoc multiple comparison test).