Acid-base transport by the renal distal nephron.
J Nephrol
; 23 Suppl 16: S19-27, 2010.
Article
in En
| MEDLINE
| ID: mdl-21170879
ABSTRACT
The functional versatility of the distal nephron is mainly due to the large cytological heterogeneity of the segment. Part of Na+ uptake by distal tubules is dependent on Na+/H+ exchanger 2 (NHE2), implicating a role of distal convoluted cells also in acid-base homeostasis. In addition, intercalated (IC) cells expressed in distal convoluted tubules, connecting tubules and collecting ducts are involved in the final regulation of acid-base excretion. IC cells regulate acid-base handling by 2 main transport proteins, a V-type H+-ATPase and a Cl/HCO3- exchanger, localized at different membrane domains. Type A IC cells are characterized by a luminal H+-ATPase in series with a basolateral Cl/HCO3- exchanger, the anion exchanger AE1. Type B IC cells mediate HCO3- secretion through the apical Cl-/HCO3- exchanger pendrin in series with a H+-ATPase at the basolateral membrane. Alternatively, H+/K+-ATPases have also been found in several distal tubule cells, particularly in type A and B IC cells. All of these mechanisms are finely regulated, and mutations of 1 or more proteins ultimately lead to expressive disorders of acid-base balance.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Acid-Base Equilibrium
/
Kidney Tubules, Distal
/
Nephrons
Limits:
Animals
/
Humans
Language:
En
Journal:
J Nephrol
Journal subject:
NEFROLOGIA
Year:
2010
Document type:
Article
Affiliation country: