Table 3.
Classification of NaV channel isoforms according to their sensitivity to TTX [72,73,75]. CNS, central nervous system; PNS, peripheral nervous system; SMCs, smooth muscle cells; DRG, dorsal root ganglion. IC50 (half maximal inhibitory concentration) is the dose that inhibits by 50% the biological function under the specified administration conditions.
| NaV Channel Isoform | Predominant Location | TTX IC50 [nM] | Sensitive/Resistant |
|---|---|---|---|
| NaV1.1 | CNS, PNS, Heart | 5.9 | Sensitive |
| NaV1.2 | CNS | 7.8 | Sensitive |
| NaV1.3 | CNS (embryonic) | 2.0 | Sensitive |
| NaV1.4 | Skeletal muscle | 4.5 | Sensitive |
| NaV1.5 | Heart, CNS | 1970 | Resistant |
| NaV1.6 | CNS, PNS, SMCs, DRG | 3.8 | Sensitive |
| NaV1.7 | PNS, DRG | 5.5 | Sensitive |
| NaV1.8 | PNS, DRG | 1330 | Resistant |
| NaV1.9 | PNS, DRG | 59,600 | Resistant |