Solute carrier family 12 member 3 (Renal sodium-chloride symporter) (NCC)

The Renal sodium-chloride symporter (NCC), encoded by the SLC12A3 gene, is a transmembrane protein primarily expressed in the apical membrane of the distal convoluted tubule (DCT) of the kidney [1, 3]. Its primary biological function is the electroneutral reabsorption of sodium and chloride ions from the primary urine back into the bloodstream, accounting for approximately 5-10% of filtered sodium [1, 4]. This process is a critical determinant of long-term blood pressure regulation and extracellular fluid volume [4]. NCC is the primary molecular target for thiazide-type diuretics, such as hydrochlorothiazide and chlorthalidone, which are widely used as first-line treatments for hypertension and edema [2]. By inhibiting NCC, these drugs increase the excretion of salt and water, thereby reducing blood volume and peripheral vascular resistance [2]. Genetic loss-of-function mutations in the SLC12A3 gene lead to Gitelman syndrome, a salt-wasting tubulopathy characterized by low blood pressure and electrolyte imbalances [4].

Other names

Na-Cl cotransporterThiazide-sensitive sodium-chloride cotransporterTSCSLC12A3

Thiazide diuretics bind to the chloride-binding site of the renal sodium-chloride symporter, competitively inhibiting the transport of sodium and chloride ions from the tubular lumen into the distal convoluted tubule cells [2, 4].