title: Phagocytosis by human macrophages is accompanied by changes in ionic channel currents.
abstract: The present study has shown that changes in ionic channel currents accompany the phagocytosis of particles by mononuclear phagocytes. The patch-clamp technique in the cell-attached configuration was applied to human monocyte-derived macrophages to measure the activity of single transmembrane ionic channels in intact cells. During such measurements, IgG-opsonized and non-opsonized latex particles were offered for phagocytosis under continuous video-microscopical observation. Single particles were presented to the phagocytes at a membrane location some distance from that of the patch electrode. After a lag period following particle attachment, enhanced inward and outward time-variant single channel currents coinciding with particle engulfment were observed. On the basis of current-voltage characteristics and membrane potential measurements, the outward-directed channels were identified as K+ channels. Phagocytosis was also accompanied by slow transient changes in background membrane currents, probably due to changes in the membrane potential of the phagocytosing cell. Phagocytosis of IgG-coated latex particles differed from phagocytosis of uncoated or albumin-coated particles by a shorter lag time between particle attachment and the onset of enhanced ionic channel activity.
authors: Department of Infectious Diseases, University Hospital, Leiden, The Netherlands.
authors: C
authors: C
authors: Ince
authors: J M
authors: JM
authors: Coremans
authors: D L
authors: DL
authors: Ypey
authors: P C
authors: PC
authors: Leijh
authors: A A
authors: AA
authors: Verveen
authors: R
authors: R
authors: van Furth
mesh_terms: D004553:Electric Conductivity; D004594:Electrophysiology; D006801:Humans; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008264:Macrophages / Q000502:physiology*; D009895:Opsonin Proteins; D010587:Phagocytosis; D011961:Receptors, Fc / Q000502:physiology
chemical_list: D007473:Ion Channels; D009895:Opsonin Proteins; D011961:Receptors, Fc