Traditionally, H+-K+ ATPases are associated with the exchange of hydrogen ions and potassium, for which they use the energy from ATP hydrolysis. These ATPases consist of a catalytic ? subunit, approximately 100 kDa in size, with 10 transmembrane helices and a catalytic site, and a glycosylated ? subunit of 30 kDa, essential for its transport and processing. In the kidney, there are two catalytic isoforms: HK? 1 (gastric) and HK? 2 (colonic). Numerous studies in nephron and collecting ducts, together with research in genetically modified mice, suggest that these ATPases transport ions other than protons and potassium. Recent evidence indicates that ATPases play a crucial role in sodium and potassium homeostasis, as well as in acid-base balance.
There is evidence that H+-K+ ATPases participate in sodium transport at the renal level. This review addresses their physiological function, regulation, and structure, highlighting their impact on sodium homeostasis and their clinical relevance in renal hypertension.
