Oxidative downmodulation of the transient K-current IA by intracellular arachidonic acid in rat hippocampal neurons.
Membrane-permeable arachidonic acid (AA) is liberated in a Ca2+-dependent way inside cells. By using whole cell patch clamp we show that intracellular AA (1 pM) selectively reduces IA in rat hippocampal neurons, whereas extracellular application requires a 10(6)-fold concentration. The nonmetabolized AA analogue ETYA mimics the effect of AA that is blocked by ascorbic acid or intracellular glutathione, suggesting an intracellular oxidative mechanism. We conclude that intracellular AA is extremely potent in reducing IA by an oxidative mechanism, particularly during oxidative stress.
AG Molekulare Zellphysiologie, Institut für Physiologie der Charité, D-10117 Berlin, Germany.
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D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000494:pharmacology; D006624:Hippocampus / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010084:Oxidation-Reduction; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D013997:Time Factors
D015221:Potassium Channels; D015117:5,8,11,14-Eicosatetraynoic Acid; D016718:Arachidonic Acid; D005978:Glutathione; D001205:Ascorbic Acid