title: Cation transport and its altered regulations in human stomatocytic erythrocytes.
abstract: Cation transport in a population of stomatocytic red blood cells (RBC) is abnormal in the following respects. First, active transport against a gradient, defined as the nonisotopic net accumulation of Na+ or loss of K+ induced by 0.1 mM ouabain, is markedly elevated (7.3 and 6.3 mEq/liter cells/hr for Na+ and K+, respectively), but the Na+:K+ active transport ratio is normal. Apparent uncoupling of the Na+ and K+ isotope transport is due to disproportionately increased ouabain-sensitive 24Na+-23Na+ exchange (32.7 mEq/liter cells/hr), which is measured as a portion of 24Na+ isotope efflux. Second, cation transport is unresponsive to variations in internal Na+ concentration but decreases with decreasing extracellular Na+.
mesh_terms: D000745:Anemia, Hemolytic, Congenital / Q000097:blood*; D001693:Biological Transport, Active; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007773:Lactates / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*
chemical_list: D007773:Lactates; D010042:Ouabain; D012964:Sodium; D011188:Potassium