Regulation of proximal bicarbonate reabsorption.
Under free-flow conditions, alterations in acid-base and extracellular volume status affect absolute proximal bicarbonate reabsorption. Microperfusion studies have characterized the individual determinants of the active and passive components of proximal acidification. These determinants include luminal bicarbonate concentration, luminal flow rate, peritubular bicarbonate concentration, PCO2, extracellular volume status, and solute-solvent interactions. When these individual determinants are integrated into a computer-simulated model of absolute proximal bicarbonate reabsorption, the results agree well with the in vivo free-flow data.
D000042:Absorption; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001696:Biomechanical Phenomena; D002118:Calcium / Q000494:pharmacology; D002245:Carbon Dioxide / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D005919:Glomerular Filtration Rate; D006863:Hydrogen-Ion Concentration; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D009399:Nephrons / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000494:pharmacology; D010281:Parathyroid Hormone / Q000494:pharmacology; D010313:Partial Pressure; D010710:Phosphates / Q000494:pharmacology; D051381:Rats
D001639:Bicarbonates; D018377:Neurotransmitter Agents; D010281:Parathyroid Hormone; D010710:Phosphates; D002245:Carbon Dioxide; D002118:Calcium