The effect of ASIC3 and TRPV1 signaling on voltage-gated sodium currents ( I
) in the acid-induced muscle pain model. (A) Representative current traces show tetrodotoxin (TTX)-sensitive and -resistant (TTXr) I
NaV evoked in medium-sized gastrocnemius muscle (GM) DRG neurons. (B) The experimental design of I
NaV analysis on muscle afferent DRG neurons. Mice were injected with 20 μL pH 7.4 saline, pH 4.0 saline, pH 4.0 saline with 20 pmole APETx2, or pH 4.0 saline with 1 nmole capsazepine. Effect of intramuscular acid injections on I
NaV in (C) non-TTXr and (D) TTXr GM DRG neurons isolated 2 days after acid injection. Effect of intramuscular acid injection on I
NaV in (E) non-TTXr and (F) TTXr GM DRG neurons isolated 5 days after acid injection. Data are mean ± SEM; *P < 0.05 and **P < 0.01 vs. pH 7.4; #P < 0.05 vs. pH4.0; $ P = 0.053 vs. pH4.0.