Sodium channel (Voltage-gated and epithelial) (Nav/ENaC)

Sodium channels are integral membrane proteins that facilitate the selective transport of sodium ions across cell membranes, playing a fundamental role in cellular excitability and fluid homeostasis. This target entry encompasses two distinct protein families: voltage-gated sodium channels (VGSCs, Nav1.1–Nav1.9) and epithelial sodium channels (ENaC) (Catterall, 2012, J Physiol; Hanukoglu & Hanukoglu, 2016, Gene). VGSCs are essential for the initiation and propagation of action potentials in neurons and muscle cells, making them critical for nervous system function and cardiac rhythm (StatPearls, 2023, Physiology, Sodium Channels). ENaCs, conversely, are non-voltage-gated channels found in epithelial tissues like the kidney and lungs, where they mediate the rate-limiting step of sodium reabsorption (Hanukoglu & Hanukoglu, 2016, Gene). Dysregulation of VGSCs is linked to epilepsy, chronic pain, and arrhythmias, while ENaC mutations are associated with Liddle syndrome and pseudohypoaldosteronism (NIH, 2023, Liddle Syndrome). Pharmacological agents targeting VGSCs include local anesthetics, anticonvulsants, and Class I antiarrhythmics, whereas ENaC is primarily targeted by potassium-sparing diuretics such as amiloride (PubChem, 2024, Amiloride). Given their widespread physiological importance, therapeutic modulation of these channels requires high subtype selectivity to mitigate risks of cardiotoxicity, neurotoxicity, or severe electrolyte imbalances (StatPearls, 2023).

Other names

Voltage-gated sodium channelsEpithelial sodium channelsNavENaCAmiloride-sensitive sodium channelsVoltage-dependent sodium channelsSCN familySCNN family

Voltage-gated sodium channel blockers inhibit the influx of sodium ions through the channel pore, preventing the depolarization phase of the action potential in excitable tissues (Catterall, 2012, J Physiol). Epithelial sodium channel blockers inhibit sodium reabsorption in the apical membrane of epithelial cells, primarily in the kidney, leading to increased sodium excretion and potassium retention (Hanukoglu & Hanukoglu, 2016, Gene).