title: Sodium channel in isolated human brain macrophages (microglia).
abstract: Human brain macrophages (microglia) have been isolated from mixed brain cell cultures initiated from explants of neurosurgical adult human tissue in one step according to a method developed for rat microglia. Cells were characterized enzyme-histochemically (NDPase) in mixed and immunocytochemically (anti-CD 14) in mixed and isolated cultures. Purified cells were used to investigate in more detail membrane currents by the patch clamp technique. In 14 cells microdialyzed with a standard, K(+)-containing intracellular solution there was no indication for a hyperpolarization-induced K(+)-inward current characteristic for newborn rat microglia. However, in 12 cells depolarizing pulses initiated a rapidly inactivating inward current which was followed by an outward current (in 4 cells). The outward current appeared to be carried by K+, since it was absent in another 18 cells, recorded by micropipettes containing Cs+ instead of K+ as the main intracellular cation. The depolarization-induced inward current persisted under these conditions. This current was inhibited by tetrodotoxin (5 microM) and by substitution of Na+ by choline in the bath solution. It is suggested that this Na(+)-current is specifically expressed in macrophages derived from adult brain.
authors.affiliation: Department of Pharmacology, University of Freiburg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Nörenberg
authors.forename: P
authors.initials: P
authors.lastname: Illes
authors.forename: P J
authors.initials: PJ
authors.lastname: Gebicke-Haerter
mesh_terms: D017766:Acid Anhydride Hydrolases; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D015214:Antigens, Differentiation, Myelomonocytic / Q000276:immunology; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002469:Cell Separation; D002478:Cells, Cultured; D004594:Electrophysiology; D006801:Humans; D018950:Lipopolysaccharide Receptors; D008264:Macrophages / Q000378:metabolism* / Q000502:physiology; D017628:Microglia / Q000378:metabolism*; D015222:Sodium Channels / Q000378:metabolism*; D013194:Staining and Labeling
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018950:Lipopolysaccharide Receptors; D015222:Sodium Channels; D017766:Acid Anhydride Hydrolases; C023837:nucleoside-diphosphatase