Investigation of monovalent cation influxes of diamide-treated human erythrocytes in solutions of different ionic strength.
Total and residual i.e. (ouabain + bumetanide + EGTA)-insensitive K+ as well as Na+ influxes were investigated in human erythrocytes before and after treatment with diamide (5 mM). In physiological and in low ionic strength solution these influxes were increased after diamide treatment. Diamide-treated cells do not exhibit significant differences between the total and residual influxes for both Na+ and K+. The diamide-induced cation fluxes in low ionic strength solution are significantly higher compared with the fluxes in physiological ionic strength solution. The diamide-induced K+ influx is not chloride-dependent, and replacement of NaCl by sodium methylsulfate does not significantly reduce this flux. A subsequent incubation of diamide-treated erythrocytes with dithioerythritol which restores the cellular glutathione level to its original value only partly decreases the enhanced K+ influx. From these results it can be concluded that electrodiffusion and K/Cl cotransport are not involved in the diamide-induced stimulation of the residual K+ influx of human erythrocytes.
Institut für Biophysik, Fachbereich Biologie, Humboldt-Universität zu Berlin, Germany.
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I
Ihrig
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Hessel
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G
Seidler
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A
Erdmann
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Bernhardt
D001692:Biological Transport / Q000187:drug effects; D003958:Diamide / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects*; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D011188:Potassium / Q000097:blood / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D012964:Sodium / Q000097:blood / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D012996:Solutions
D012996:Solutions; D003958:Diamide; D012965:Sodium Chloride; D011189:Potassium Chloride; D012964:Sodium; D011188:Potassium