Preferred Label : Proximal Tubule Bicarbonate Reclamation Pathway;
NCIt related terms : Proximal tubule bicarbonate reclamation;
Alternative definition : KEGG: One of the major tasks of the renal proximal tubule (PT) is to secrete acid
into the tubule lumen, thereby reabsorbing approximately 80% of the filtered bicarbonate
(HCO3(-)), as well as generating new HCO3(-) for regulating blood pH. In the tubular
lumen, filtered HCO3(-) combines with H( ) in a reaction catalyzed by CA IV. The CO2
thus produced rapidly diffuses into the tubular cells and is combined with water to
produce intracellular H( ) and HCO3(-), catalyzed by soluble cytoplasmic CA II. HCO3(-)
is then cotransported with Na( ) into blood via the NBC-1. The intracellular H( )
produced by CA II is secreted into the tubular lumen predominantly via the NHE-3.
The PT creates the new HCO3(-) by taking glutamine and metabolizing it to two molecules
each of NH4( ) and HCO3(-). The NH4( ) is excreted into the tubular lumen, and the
HCO3(-), which is new HCO3(-), is returned to the blood, where it replaces the HCO3(-)
lost earlier in the titration of nonvolatile acids.;
KEGG ID : hsa04964;
Origin ID : C91494;
UMLS CUI : C2984305;
Semantic type(s)
- has_gene_product_element
- pathway_has_gene_element
