Intracellular Regulation of Ion Channels pp 43-52 | Cite as
Receptor-Dependent Modulation of G Protein-Gated Muscarinic K+ Channel by Arachidonic Acid Metabolites
Abstract
Intracellular 5-lipoxygenase metabolites of arachidonic acid were found to modulate the cardiac G protein (GK)-gated muscarinic K+ channel (KACh) in a stimulatory manner. The pathway could be activated by various receptor agonists, such as phenylephrine (α1-adrenergic agonist) and platelet-activating factor. The arachidonic acid metabolite-mediated activation of the KACh channel was independent from muscarinic ACh and adenosine receptors, which are directly coupled to GK. However, the activation was dependent on intracellular GTP and was inhibited by GDP-βS, suggesting arachidonic acid metabolites may directly stimulate GK.
Key Words
muscarinic K+ channel arachidonic acid 5-lipoxygenase G proteinPreview
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