Solute carrier family 12 member 3 (Sodium-chloride cotransporter) (NCC)

The Solute carrier family 12 member 3, commonly known as the Sodium-chloride cotransporter (NCC), is a transmembrane protein primarily expressed on the apical membrane of the distal convoluted tubule (DCT) in the kidney [UniProt P55017]. Its primary biological function is the electroneutral reabsorption of sodium and chloride ions from the tubular fluid back into the blood, accounting for approximately 5-10% of filtered sodium [PubMed: 25601066]. This process is critical for maintaining systemic blood pressure and electrolyte homeostasis. NCC is the primary pharmacological target for thiazide and thiazide-like diuretics, which are widely used as first-line treatments for hypertension and edema [StatPearls: Thiazide Diuretics]. By inhibiting NCC, these drugs promote natriuresis and diuresis, thereby reducing extracellular fluid volume and blood pressure. Genetic loss-of-function mutations in the SLC12A3 gene lead to Gitelman syndrome, a salt-wasting tubulopathy, while gain-of-function or over-activation is linked to salt-sensitive hypertension [NIH: Genetics Home Reference].

Other names

SLC12A3Thiazide-sensitive sodium-chloride cotransporterTSCNa-Cl symporterSodium-chloride cotransporter

Thiazide diuretics competitively inhibit the chloride-binding site of the NCC protein on the apical membrane of the distal convoluted tubule, thereby blocking the electroneutral reabsorption of sodium and chloride ions [StatPearls: Thiazide Diuretics].