Plasma membrane potential of neutrophils generated by the Na+ pump.
The plasma membrane potential of human neutrophils was monitored using the anionic dye oxonol-V. The cells maintain a potential of -75 +/- 17 mV when suspended in physiological saline solutions. The cells are scarcely depolarized by extracellular K+ and the depolarization induced by the chemotactic peptide fMet-Leu-Phe is of similar magnitude for cells suspended in 5 or 155 mM K+. Neutrophils are, however, depolarized by suspension in K+-free media or after treatment with ouabain. Neutrophils catalyse Na+-H+ exchange and possess other electroneutral ion transport systems. We propose that the neutrophil membrane potential is generated by an electrogenic Na+ pump, that osmotic stability is achieved by electroneutral ion transport systems and that electrical stability is maintained by anion leakage. Similar mechanisms may also operate in other biological membranes.
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Bashford
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Pasternak
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002286:Carcinoma, Ehrlich Tumor / Q000503:physiopathology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008214:Lymphocytes / Q000502:physiology; D008564:Membrane Potentials; D051379:Mice; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000097:blood*
D007473:Ion Channels; D009240:N-Formylmethionine Leucyl-Phenylalanine; D012964:Sodium; D011188:Potassium