Abstract
Whole-cell membrane currents were recorded from olfactory receptor neurons from the neotenic salamander Necturus maculosus. Cyclic nucleotides, released intracellularly by flash photolysis of NPE-caged cAMP or NPE-caged cGMP, activated a transient chloride current. The chloride current could be elicited at constant voltage in the absence of extracellular Ca2+ as well as in the presence of 3 mM intracellular Ca2+, suggesting that the current did not require either voltage or Ca2+ transients for activation. The current could be elicited in the presence of the protein kinase inhibitors H-7 and H-89, and in the absence of intracellular ATP, indicating that activation was independent of protein kinase A activity. These results suggest that Necturus olfactory receptor neurons contain a novel chloride ion channel that may be directly gated by cyclic nucleotides.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / pharmacology
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Adenosine Triphosphate / pharmacology
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Animals
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Calcium / metabolism*
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Calcium / pharmacology
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Chloride Channels / drug effects
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Chloride Channels / physiology*
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Cyclic AMP / analogs & derivatives
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Cyclic AMP / pharmacology*
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Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
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Cyclic AMP-Dependent Protein Kinases / metabolism
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Cyclic GMP / analogs & derivatives
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Cyclic GMP / pharmacology*
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Enzyme Inhibitors / pharmacology
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In Vitro Techniques
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Isoquinolines / pharmacology
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Necturus
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Olfactory Receptor Neurons / physiology*
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Patch-Clamp Techniques
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Photolysis
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Sulfonamides*
Substances
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Chloride Channels
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Enzyme Inhibitors
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Isoquinolines
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Sulfonamides
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Adenosine Triphosphate
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Cyclic AMP
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Cyclic AMP-Dependent Protein Kinases
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Cyclic GMP
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N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide
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Calcium