Abstract
Functional gap junctional communication between vascular cells has been implicated in ascending dilatation and the cytochrome P-450 (CYP) inhibitor-sensitive and NO- and prostacyclin-independent dilatation of many vascular beds. Here, we assessed the mechanisms by which the epoxyeicosatrienoic acids (EETs) generated by a CYP 2C enzyme control interendothelial gap junctional communication. In CYP 2C-expressing porcine coronary endothelial cells, bradykinin, which enhances EET formation, elicited a biphasic effect on the electrical coupling and transfer of Lucifer yellow between endothelial cells, consisting of a transient increase in coupling followed by a sustained uncoupling. The initial phase was sensitive to the CYP 2C9 inhibitor sulfaphenazole and the protein kinase A (PKA) inhibitors Rp-cAMPS and KT5720 and could be mimicked by forskolin and caged cAMP as well as by the PKA activators 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole 3',5'-cyclic monophosphorothioate sodium salt and Sp-cAMPS. Gap junction uncoupling in bradykinin-stimulated porcine coronary endothelial cells was prevented by inhibiting the activation of extracellular signal-regulated kinase (ERK)1/2. In human endothelial cells, which express little CYP 2C, bradykinin elicited only an ERK1/2-mediated inhibition of intercellular communication. The CYP 2C9 product, 11,12-EET, also exerted a dual effect on the electrical and dye coupling of human endothelial cells, which was sensitive to PKA inhibition. These results demonstrate that an agonist-activated CYP-dependent pathway as well as 11,12-EET can positively regulate interendothelial gap junctional communication, most probably via the activation of PKA, an effect that is curtailed by the subsequent activation of ERK1/2.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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8,11,14-Eicosatrienoic Acid / analogs & derivatives*
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8,11,14-Eicosatrienoic Acid / pharmacology*
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Animals
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Aryl Hydrocarbon Hydroxylases*
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Biological Transport / drug effects
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Bradykinin / pharmacology
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Cell Communication / drug effects*
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Cell Communication / physiology
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Cells, Cultured
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Colforsin / pharmacology
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Connexin 43 / metabolism
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Cyclic AMP / analogs & derivatives*
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Cyclic AMP / pharmacology
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Cyclic AMP-Dependent Protein Kinases / drug effects
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Cyclic AMP-Dependent Protein Kinases / metabolism
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Cytochrome P-450 Enzyme Inhibitors
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Cytochrome P-450 Enzyme System / genetics
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Cytochrome P-450 Enzyme System / metabolism
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Endothelium, Vascular / cytology
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Endothelium, Vascular / drug effects*
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Endothelium, Vascular / metabolism
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Enzyme Activators / pharmacology
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Enzyme Inhibitors / pharmacology
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Fluorescent Dyes / pharmacokinetics
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Gap Junctions / drug effects*
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Gap Junctions / metabolism
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Humans
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Isoquinolines / pharmacokinetics
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Mitogen-Activated Protein Kinase 1 / antagonists & inhibitors
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases / antagonists & inhibitors
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Patch-Clamp Techniques
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RNA, Messenger / metabolism
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Signal Transduction / drug effects
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Signal Transduction / physiology
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Steroid 16-alpha-Hydroxylase*
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Steroid Hydroxylases / antagonists & inhibitors
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Steroid Hydroxylases / genetics
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Steroid Hydroxylases / metabolism
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Swine
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Vasodilator Agents / pharmacology
Substances
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(2-nitrophenyl)ethyl-cyclic adenosine monophosphate
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Connexin 43
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Cytochrome P-450 Enzyme Inhibitors
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Enzyme Activators
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Enzyme Inhibitors
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Fluorescent Dyes
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Isoquinolines
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RNA, Messenger
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Vasodilator Agents
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Colforsin
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11,12-epoxy-5,8,14-eicosatrienoic acid
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Cytochrome P-450 Enzyme System
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lucifer yellow
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Cyclic AMP
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Steroid Hydroxylases
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Aryl Hydrocarbon Hydroxylases
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Steroid 16-alpha-Hydroxylase
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Cyclic AMP-Dependent Protein Kinases
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Mitogen-Activated Protein Kinase 1
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Mitogen-Activated Protein Kinase 3
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Mitogen-Activated Protein Kinases
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8,11,14-Eicosatrienoic Acid
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Bradykinin