Study on the dehydrating effect of the red cell Na+/K+-pump in nystatin-treated cells with varying Na+ and water contents.
Using the antibiotic Nystatin, we have developed a systematic method for the preparation of red blood cells with independently selected levels of intracellular Na+ concentrations and water content. Such cells provided an experimental model to study the effect of Na+/K+ pump stimulation on red cell water content. Even in initially dehydrated cells, stimulation of the Na+/K+ pump by elevated intracellular Na+ caused subsequent further loss of cell water. Cell water loss was reflected in decreased monovalent cation content per unit mass of hemoglobin and by a shift in the density distribution of the cell populations to higher densities on discontinuous Stractan gradients. We conclude that the 3 Na+out : 2 K+in stoichiometry of the Na+/K+ pump results in a net desalting effect with increased pump activity. Under the conditions of these experiments, the cell appears to have no effective mechanism to compensate for a net loss of ions and water.
D000255:Adenosine Triphosphate / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D009761:Nystatin / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood*; D014867:Water / Q000378:metabolism*
D014867:Water; D009761:Nystatin; D010042:Ouabain; D000255:Adenosine Triphosphate; D012964:Sodium; D011188:Potassium