NKCC1 is one of two Na-K-Cl cotransporter isoforms that have been identified. NKCC1 is present in a wide variety of secretory epithelia and non-epithelial cells. NKCC1 is expressed in virtually all mammalian cells and is thought to play a housekeeping role in cell volume homeostasis and the common control of cytosolic ion content. NKCC1 does not use ATP but operates using electrochemical gradient for Na+ and K+ produced by Na+-K+-ATPase4. There is considerable evidence that uptake of Cl? in immature neurons is mediated by NKCC1. High expression of NKCC1 in immature neurons plays an important role in maintaining high intracellular Cl?
