2010年3月19日 · The other isoforms, which are predominantly expressed in the skeletal muscle and nervous system, are highly sensitive to TTX (IC50 ~ 10 nM). During the last two decades, it has become evident that in addition to the major cardiac isoform Nav1.5, several of those TTX sensitive isoforms are expressed in the mammalian heart.

2014年12月31日 · Mammalian species express nine functional voltage-gated Na (+) channels. Three of them, the cardiac-specific isoform Nav1.5 and the neuronal isoforms Nav1.8 and Nav1.9, are relatively resistant to the neurotoxin tetrodotoxin (TTX; IC50 ≥ 1 μM). The other six isoforms are highly sensitive to TTX with IC50 values in the nanomolar range.

Nav1.7 is a pivotal player in acute and inflammatory pain with good sensitivity to TTX (IC50 2 nM) . The Nav1.8 and 1.9 TTX-resistant channels are predominant in nociceptive unmyelinated C fibres and are associated with the perception of nociceptive cold and pain at cold temperatures , and hypersensitivity to inflammatory pain , respectively.

The results indicate that TTX at 3-10 nM could block most of voltage-dependent Na(+) channels on presynaptic nerve terminal, resulting in abruptly inhibition of action potential dependent excitatory neurotransmission.

能有效的阻滞人重组Nav1.8通道（IC50=11nM），阻滞Nav1.8的的强度不低于阻滞TTX-S钠离子通道的10倍，是阻滞河豚毒素不敏感性Nav1.5的30倍以上。 这说明了A-887826是Nav1.8的高选择性和高强度阻滞剂。

A-887826 是一种强效、选择性、口服生物利用性和电压依赖性 Na(v)1.8 钠通道阻滞剂，IC50 为 11 nM。A-887826 可减轻体内神经性触觉过敏。

2022年5月31日 · 若从药理学角度分类，可以将钠离子通道分为两大类：河豚毒素（tetrodotoxin，TTX）敏感型（TTX-S）和河豚毒素不敏感型（TTX-R）。 人体中Nav1.1，Nav1.2，Nav1.3，Nav1.4，Nav1.6和Nav1.7属于河豚毒素敏感型。

1986年3月18日 · Electrophysiological experiments showed that high concentrations of Cd2+ (IC50 = 2 mM) are necessary to inhibit both TTX-sensitive and TTX-insensitive Na+ channels when the channels are activated by voltage steps.