Biomaterial Database

Na,K-pump expression and distribution in the nephron. 1996

N Farman

INSERM U246, IFR, Cellules Epithéliales, Faculté de Médecine X. Bichat, Paris, France.

Na+,K(+)-ATPase plays a major role in the reabsorption of sodium by the kidney. This organ is highly heterogeneous, and its functional unit, the nephron, is formed of successive epithelia with specific morphological and functional characteristics. Na+,K(+)-ATPase expression varies along the nephron. Variations in the catalytic activity of the pump, the number of active pumps expressed in the basolateral membrane, its substrate dependency towards Na and K, and its sensitivity to the inhibitor ouabain have been observed in distinct tubular segments. Most authors agree on the large (or unique) prevalence of the alpha 1 and beta 1 isoforms of the two subunits of Na+,K(+)-ATPase in each nephron segment, although at different levels. The cortical collecting duct represents a unique epithelium to study the physiological relevance of the regulation of Na+,K(+)-ATPase activity, including an immediate substrate activation, a rapid recruitment of active pumps from a reserve pool, and long-term hormonal effects. Whether these functions require other molecular determinants than the alpha 1 and beta 1 isoform subunits remains to be established.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D009399	Nephrons	The functional units of the kidney, consisting of the glomerulus and the attached tubule.	Nephron
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D000254	Sodium-Potassium-Exchanging ATPase	An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.	ATPase, Sodium, Potassium,Adenosinetriphosphatase, Sodium, Potassium,Na(+)-K(+)-Exchanging ATPase,Na(+)-K(+)-Transporting ATPase,Potassium Pump,Sodium Pump,Sodium, Potassium ATPase,Sodium, Potassium Adenosinetriphosphatase,Sodium-Potassium Pump,Adenosine Triphosphatase, Sodium, Potassium,Na(+) K(+)-Transporting ATPase,Sodium, Potassium Adenosine Triphosphatase,ATPase Sodium, Potassium,ATPase, Sodium-Potassium-Exchanging,Adenosinetriphosphatase Sodium, Potassium,Pump, Potassium,Pump, Sodium,Pump, Sodium-Potassium,Sodium Potassium Exchanging ATPase,Sodium Potassium Pump
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia