title: Calcium accumulation in human and sheep erythrocytes that is induced by Escherichia coli hemolysin.
abstract: The membrane permeability of both human and sheep erythrocytes is modified by an Escherichia coli-produced extracellular hemolysin. Alterations in membrane permeability were determined by measuring changes in the extracellular concentration of radiolabeled compounds that had been added to a 30-35% erythrocyte suspension. During the pre-lytic period, the E. coli hemolysin promotes calcium accumulation by both human and sheep erythrocytes. The concentration of calcium associated with the cells rises to a level that is approximately 1.5 (sheep) to 3 (human) times higher than that in a comparable volume of extracellular solution. Hemolysin also causes a rapid depletion of the high intracellular potassium levels normally present in human erythrocytes. That neither inulin, sucrose nor phosphate is accumulated by hemolysin-treated erythrocytes indicates that hemolysin makes the membrane selectively permeable to cations.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D004926:Escherichia coli / Q000032:analysis*; D006460:Hemolysin Proteins / Q000502:physiology*; D006461:Hemolysis; D006801:Humans; D066298:In Vitro Techniques; D010710:Phosphates / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012756:Sheep
chemical_list: D006460:Hemolysin Proteins; D010710:Phosphates; D011188:Potassium; D002118:Calcium