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. Author manuscript; available in PMC: 2009 Oct 14.
Published in final edited form as: Anesthesiology. 2009 Jul;111(1):127–137. doi: 10.1097/ALN.0b013e3181a915e7

Fig. 7. The prolonged analgesic effect of the lidocaine–QX-314 combination depends largely, but not exclusively, on activation of transient receptor potential vanilloid1 (TRPV1) channels. (A) In TRPV1 knockout (KO) mice, the duration of the elevation of mechanical threshold assessed using von Frey hairs after combined injection of lidocaine and QX-314 (0.2% QX-314, 5% lidocaine, 10 μl, n = 6) is significantly shorter than in wild type (WT) animals (P < 0.0001, analysis of variance [ANOVA], n = 4), but it exceeds that produced by lidocaine alone (5%, 10 μl; P < 0.05, ANOVA, n = 4). Lidocaine alone (5%, 10 μl) produced similar effects in TRPV1 KO and WT animals (P = 0.4, n = 4, two-way ANOVA). Injection of QX-314 alone (0.2%, 10 μl) did not change mechanical threshold both in TRPV1 KO and WT mice (n = 4). * P < 0.05. (B) Representative traces from two cells (black and gray) recorded simultaneously during consecutive application of lidocaine (20 s, 30 mm) and capsaicin (20 s, 1 μm). Lidocaine induces an increase in intracellular calcium concentration (increase in fluorescent ratio [ΔF340/380]) through both TRPV1-dependent (capsaicin-sensitive) and TRPV1-independent mechanisms.

Fig. 7