Abstract
The human neuroblastoma cell line SH-SY5Y expresses the 'orphan' opioid receptor (ORL1). We have demonstrated that nociceptin, the putative endogenous ligand for ORL1, produces a concentration-dependent inhibition of the N-type calcium channel current in these cells (IC50 42 nM). In addition, in the presence of carbachol, nociceptin increased the intracellular concentration of Ca2+ (EC50 60 nM). Both effects of nociceptin were blocked by pertussis toxin pretreatment but not by the opioid antagonists CTAP (1 microM), naltrindole (1 microM) and naloxone (10 microM).
MeSH terms
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Amino Acid Sequence
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Calcium / metabolism*
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Calcium Channel Blockers / pharmacology*
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Carbachol / pharmacology
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Enzyme Inhibitors / pharmacology
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Humans
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Molecular Sequence Data
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Narcotic Antagonists / pharmacology
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Neuroblastoma
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Nociceptin
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Opioid Peptides / antagonists & inhibitors
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Opioid Peptides / pharmacology*
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Pertussis Toxin
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Receptors, Opioid / agonists
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Tumor Cells, Cultured
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Virulence Factors, Bordetella / pharmacology
Substances
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Calcium Channel Blockers
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Enzyme Inhibitors
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Narcotic Antagonists
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Opioid Peptides
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Receptors, Opioid
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Virulence Factors, Bordetella
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Carbachol
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Pertussis Toxin
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Calcium