Proximal tubule bicarbonate reclamation
| PAG Title | Proximal tubule bicarbonate reclamation |
| PAG ID | WIG000602 |
| Type | P |
| Source Link |  MSigDB |
| Publication Reference | NA |
| PAG Description | 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. |
| Species | Homo sapiens |
| nCoCo Score | 485 |
| Base PAG ID | WIG000602 |
| Human Phenotyte Annotation | |
| Curator | PAGER curation team |
| Curator Contact | PAGER-contact@googlegroups.com |
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