Induction of outward current by orexin-B in mouse peritoneal macrophages.
To define effects of novel feeding regulating peptides, orexins, in immunocompetent cells, ion channel activity in mouse peritoneal macrophages was analyzed by the perforated patch-clamp method. Orexin-B (OX-B) induced an outward current at smaller holding potentials than K+ equilibrium potentials. Reversal potentials of OX-B induced current were dependent on external K+ concentrations but not on external Cl- concentration. Orexin-A is less effective than OX-B. Quinine blocked the outward current and tetraethylammonium partially suppressed the current. These results suggest that OX-B can modulate macrophage functions through the activation of Ca2+-dependent K2+ channels.
Ichinose
M
M
Department of Physiology, Shimane Medical University, Izumo, Japan. michinos@shimane-med.ac.jp
Asai
M
M
Sawada
M
M
Sasaki
K
K
Oomura
Y
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000494:pharmacology; D018999:Charybdotoxin / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000494:pharmacology; D005260:Female; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D009479:Neuropeptides / Q000494:pharmacology*; D000068797:Orexins; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology*; D011506:Proteins / Q000494:pharmacology; D011803:Quinine / Q000494:pharmacology; D012633:Secretin / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology
D002352:Carrier Proteins; D002712:Chlorides; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D009479:Neuropeptides; D000068797:Orexins; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011506:Proteins; D018999:Charybdotoxin; D012633:Secretin; D004533:Egtazic Acid; D019789:Tetraethylammonium; D011803:Quinine; D011188:Potassium; D002118:Calcium