title: Electrophysiology of phagocytic membranes. I. Potassium-dependent slow membrane hyperpolarizations in mice macrophages.
abstract: Electrophysiological properties of activated mouse macrophages cultured in vitro were studied using microelectrode techniques. In a high percentage of the individual cells analysed a slow hyperpolarization (SH) was observed with a concomitant decrease (2--4 times) of the input resistance. Increasing doses of tetraethyl ammonium progressively reduce the amplitude of the SH and at a concentration of 15 mM complete blockade of the phenomena is observed. Valinomycin, at a concentration of 10(-7) M produces rapid and permanent hyperpolarization, with a shift in the membrane potential to about --50 mV. These data strongly support the previously proposed hypothesis that the development of SH is due to an increase in the membrane permeability to potassium ions.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D008264:Macrophages / Q000378:metabolism / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008839:Microelectrodes; D011188:Potassium / Q000378:metabolism*; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D013757:Tetraethylammonium Compounds; D014634:Valinomycin; D011188:Potassium