Solute carrier family 12 member 1 and Solute carrier family 12 member 3 (NKCC2 and NCC)

The Solute Carrier Family 12 Member 1 (NKCC2) and Solute Carrier Family 12 Member 3 (NCC) are distinct renal transporters responsible for the majority of salt reabsorption in the thick ascending limb and distal convoluted tubule, respectively (UniProt Q13621, P55017). NKCC2 facilitates the symport of one sodium, one potassium, and two chloride ions, while NCC mediates the symport of one sodium and one chloride ion (NIH Gene SLC12A1, SLC12A3). These proteins are the primary targets for two major classes of diuretics: loop diuretics (e.g., furosemide) target NKCC2, and thiazide-type diuretics (e.g., hydrochlorothiazide) target NCC (StatPearls, Diuretics). Both transporters play a vital role in maintaining extracellular fluid volume and systemic blood pressure. Genetic mutations in these transporters lead to salt-losing tubulopathies, specifically Bartter syndrome type 1 for NKCC2 and Gitelman syndrome for NCC (PubMed PMID: 29438332). Pharmacological inhibition of these transporters is a cornerstone in treating hypertension, congestive heart failure, and various edematous states. However, their inhibition can lead to significant electrolyte imbalances, most notably hypokalemia and hyponatremia, requiring careful clinical monitoring (StatPearls, Loop Diuretics).

Other names

SLC12A1SLC12A3NKCC2NCCBSC1TSCNa-K-2Cl cotransporter 2Renal sodium-chloride cotransporterThiazide-sensitive sodium-chloride cotransporterBumetanide-sensitive sodium-(potassium)-chloride cotransporter 2

Inhibition of the Na-K-2Cl cotransporter (NKCC2) in the thick ascending limb of the loop of Henle and the Na-Cl cotransporter (NCC) in the distal convoluted tubule, leading to increased urinary excretion of sodium, chloride, and water.