title: Effect of acute hypoxia on ATP-sensitive potassium currents in substantia gelatinosa neurons of juvenile rats.
abstract: Although hypoxia is known to affect membrane excitability of various neurons by various mechanisms, the effects of hypoxia on substantia gelatinosa (SG) neurons have not yet been elucidated. In whole-cell or perforated patch-clamp recordings from SG neurons, we showed that acute hypoxia induces a reversible hyperpolarization of -6.1+/-1.3 mV of the resting membrane potential and an outwards current of 9.48+/-1.71 pA at a holding potential of -60 mV. The reversal potentials of the hypoxia-induced current depended on [K(+)](o). The hypoxia-induced hyperpolarization and outwards current were abolished completely by BaCl(2), but not by CsCl. Glibenclamide, a blocker of K(ATP) channels, blocked the hypoxia-induced hyperpolarization. Pretreatment with cromakalim, an opener of K(ATP) channels, occluded the hypoxia-induced hyperpolarization. Any alteration by hypoxia was not observed in the presence of an internal solution with a high [ATP] (10 mM). The above results suggest that hypoxia-induced hyperpolarization in SG neurons is mediated by activation of K(ATP) channels.
authors.affiliation: Department of Biomedical Science, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
authors.forename: Yun Kyung
authors.initials: YK
authors.lastname: Park
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Jung
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Yoo
authors.forename: Jiyeon
authors.initials: J
authors.lastname: Kwak
authors.forename: Wonil
authors.initials: W
authors.lastname: Lim
authors.forename: Jun
authors.initials: J
authors.lastname: Kim
mesh_terms: D000208:Acute Disease; D000255:Adenosine Triphosphate / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001464:Barium / Q000494:pharmacology; D002586:Cesium / Q000494:pharmacology; D019806:Cromakalim / Q000494:pharmacology; D005905:Glyburide / Q000494:pharmacology; D000860:Hypoxia / Q000503:physiopathology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010276:Parasympatholytics / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D013376:Substantia Gelatinosa / Q000166:cytology / Q000502:physiology*
chemical_list: D000889:Anti-Arrhythmia Agents; D010276:Parasympatholytics; D015221:Potassium Channels; D019806:Cromakalim; D002586:Cesium; D001464:Barium; D000255:Adenosine Triphosphate; D005905:Glyburide