Function of K(+)-Cl(-) Cotransporters in the Acid Secretory Mechanism of Gastric Parietal Cells

摘要

Gastric proton pump (H(+), K(+)-ATPase) secretes H(+) of acid (HCl) via the luminal membrane of parietal cells. For the HCl secretion, Cl(-)- and K(+)-transporting proteins are required. Recent our studies have demonstrated that K(+)-Cl(-) cotransporters (KCC3a and KCC4) are expressed in gastric parietal cells. KCC3a is associated with Na(+), K(+)-ATPase in the basolateral membrane, and KCC4 is associated with H(+), K(+)-ATPase in the apical canalicular membrane. This paper summarizes the functional association between KCCs and P-type ATPases and the contribution of these complexes to acid secretion in gastric parietal cells.