Abstract
Depletion of intracellular calcium stores by agonist stimulation is coupled to calcium influx across the plasma membrane, a process termed capacitative calcium entry. Capacitative calcium entry was examined in cultured guinea pig enteric glial cells exposed to endothelin 3. Endothelin 3 (10 nM) caused mobilization of intracellular calcium stores followed by influx of extracellular calcium. This capacitative calcium influx was inhibited by Ni2+ (89 +/- 2%) and by La3+ (78 +/- 2%) but was not affected by L-, N-, or P-type calcium channel blockers. Chelerythrine, a specific antagonist of protein kinase C, dose-dependently inhibited capacitative calcium entry. The nitric oxide synthase inhibitor NG-nitro-L-arginine decreased calcium influx in a dose-dependent manner. The combination of chelerythrine and NG-nitro-L-arginine produced synergistic inhibitory effects. Capacitative calcium entry occurs in enteric glial cells via lanthanum-inhibitable channels through a process regulated by protein kinase C and nitric oxide.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alkaloids
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Animals
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Benzophenanthridines
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Calcium / metabolism*
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Calcium Channels / metabolism
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Carcinogens / pharmacology
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Cells, Cultured
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Drug Synergism
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Endothelin-3 / pharmacology*
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Enzyme Inhibitors / pharmacology
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Guinea Pigs
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Myenteric Plexus / cytology
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Neuroglia / chemistry
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Neuroglia / drug effects
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Neuroglia / enzymology*
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Nickel / pharmacology
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Nitric Oxide / metabolism*
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Nitric Oxide Synthase / metabolism
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Nitroarginine / pharmacology
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Penicillamine / analogs & derivatives
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Penicillamine / pharmacology
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Phenanthridines / pharmacology
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Protein Kinase C / metabolism*
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Staurosporine / pharmacology
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Tetradecanoylphorbol Acetate / pharmacology
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omega-N-Methylarginine / pharmacology
Substances
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Alkaloids
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Benzophenanthridines
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Calcium Channels
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Carcinogens
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Endothelin-3
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Enzyme Inhibitors
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Phenanthridines
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S-nitro-N-acetylpenicillamine
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Nitroarginine
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omega-N-Methylarginine
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Nitric Oxide
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Nickel
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chelerythrine
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Nitric Oxide Synthase
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Protein Kinase C
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Penicillamine
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Staurosporine
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Tetradecanoylphorbol Acetate
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Calcium