title: Alkali metal cation transport through the human erythrocyte membrane by the anion exchange mechanism.
abstract: This work deals with the possibility that cations may be transported through the human red blood cell membrane as negatively charged ion pairs of the type XCO3-. Passive sodium influx into human erythrocytes was increased 4-fold when 150 mM chloride was substituted with bicarbonate in the medium. This increased permeability to sodium was completely abolished when the cells were pretreated with a specific inhibitor of anion transport (DIDS). Both bicarbonate-induced sodium influx and chloride exchange were linearly related to DIDS-binding. Both transport processes were completely inhibited by the binding of 1.1 X 10(6) DIDS molecules per cell. The presence of bicarbonate and/or pretreatment of the cells with DIDS did not change the permeability of the erythrocyte membrane to K+, Rb+, and Cs+ to any significant extent. The experimental findings support the hypothesis that Li+ and Na+, but not K+, Rb+, and Cs+ form monovalent negatively charged ion pairs with CO3--, which traverse the membrane through the anion exchange system.
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D001639:Bicarbonates / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002586:Cesium / Q000097:blood; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007474:Ion Exchange; D008094:Lithium / Q000097:blood; D008672:Metals, Alkali / Q000097:blood*; D011188:Potassium / Q000097:blood; D012413:Rubidium / Q000097:blood; D012964:Sodium / Q000097:blood
chemical_list: D001639:Bicarbonates; D008672:Metals, Alkali; D002586:Cesium; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D008094:Lithium; D012964:Sodium; D012413:Rubidium; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D011188:Potassium