Activation of K+ current in macrophages by platelet activating factor.
Puff application of platelet activating factor (10(-8) M) onto peritoneal macrophages from thioglycollate-stimulated mice induced an outward current at a holding potential of -63 mV. The current was suppressed by an antagonist Y-24180 but not by CV-3988. Charybdotoxin (10(-6) M) suppressed the current. Reversal potentials were dependent on external K+ concentrations. The current was not suppressed in Ca(2+)-free EGTA-containing solution but was completely abolished in BAPTA-AM containing solution. These results suggest that platelet activating factor activates a Ca(2+)-dependent K+ channel.
Department of Physiology, Shimane Medical University, Izumo, Japan.
M
M
Ichinose
N
N
Hara
M
M
Sawada
T
T
Maeno
D000818:Animals; D002478:Cells, Cultured; D018999:Charybdotoxin; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D004594:Electrophysiology / Q000379:methods; D005260:Female; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008809:Mice, Inbred C3H; D010972:Platelet Activating Factor / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D012604:Scorpion Venoms / Q000494:pharmacology; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D010972:Platelet Activating Factor; D015221:Potassium Channels; D012604:Scorpion Venoms; D013757:Tetraethylammonium Compounds; D018999:Charybdotoxin; D004533:Egtazic Acid; D019789:Tetraethylammonium