Bicarbonate, along with CO2, is the major pH buffer of biological fluids.
The inter-conversion of CO2 to HCO3- is mediated by family of carbonic anhydrases.
Several organs specialize in the mobilization of HCO3-.
The pancreatic ducts move CO2 and HCO3- from the blood into pancreatic secretions.
The kidneys reabsorb massive amount of HCO3- daily (amount of NaHCO3 contained in 1 Ib of baking soda) through the glomerular flirtation of ~180 liters of plasma.
To prevent a massive acidosis, the proximal tubules (PT) cells in the nephron subsequently reabsorb virtually all of HCO3-, as well as most of the filtered Na+, Cl-, and H2O.
A great majority of HCO3- reabsorption occurs via trans-cellular coupling of the luminal Na-H+ exchanger 3 and Na+-H+ ATPase with the basolateral Na+ HCO3- cotransporters (NBC).
NBC3 (SLC4A); mouse (1089 aa, human 1044 aa) has 3 three transcripts, which are expressed in a tissue specific manner (9 kb in brain, placenta, lung, liver, muscle, kidney, pancreas, stomach, thyroid, and adrenal etc).
NBC3 has two variants.
NBC3 is 56% identical with NBC1 and 76% with NBC2.
Applications:Suitable for use in ELISA.
Western Blot, though not tested, may potentially be used as an application.