H,K-ATPase.

At least four unique H,K-ATPases have been cloned and are expressed in several tissues. Recent findings have enhanced our appreciation of the roles of H,K-ATPases in the kidney with respect to their molecular identities, functional properties, segmental and intrarenal distribution, and regulatory features. The major role of the H,K-ATPases expressed in mammalian kidney, the gastric and colonic H,K-ATPases, is to regulate potassium and bicarbonate absorption in collecting duct segments.