[The role of HCO3- ATPase in H+ /HCO3-Secretion (author's transl)].
Active buffer transport, e.g. H+ -secretion by stomach and kidney and HCO3--secretion by pancreas and salivary glands, is linked with the presence of a HCO3-stimulated ATP-Phosphohydrolase. In contrast to (Na+ -k+)-ATPase which is considered to be equivalent to the Na+ pump, the HCO3--ATPase requires only one ion for activation and is insensitive to ouabain. The HCO3--ATPase is found in the plasma membrane of the epithelia, but in contrast to the (Na+ -k+)-ATPase it is located in the luminal cell border. The activity of the HCO3--ATPase changes in parallel along with the rate of active buffer transport, a finding which underlines its importance as a transport enzyme. Several disorders of buffer transport are described which are possibly associated with a defect of the HCO3--ATPase system.
D000251:Adenosine Triphosphatases / Q000502:physiology*; D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001693:Biological Transport, Active; D004791:Enzyme Inhibitors; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology; D008954:Models, Biological; D010042:Ouabain / Q000494:pharmacology; D010179:Pancreas / Q000201:enzymology / Q000378:metabolism; D010743:Phospholipids / Q000502:physiology; D051381:Rats; D013270:Stomach / Q000201:enzymology; D013363:Submandibular Gland / Q000201:enzymology / Q000378:metabolism
D001639:Bicarbonates; D004791:Enzyme Inhibitors; D010743:Phospholipids; D010042:Ouabain; D000251:Adenosine Triphosphatases
Die Bedeutung der HCO3--ATPase in der H+ /HCO3--Sekretion