Synergism in cytosolic Ca2+ mobilization between bradykinin and agonists for pertussis toxin-sensitive G-protein-coupled receptors in NG 108-15 cells.
Bradykinin (BK) induced a transient and pertussis toxin (PT)-insensitive increase in cytosolic Ca2+ ([Ca2+]i) in NG 108-15 neuroblastoma x glioma hybrid cells, whereas leucine-enkephalin (EK), somatostatin, norepinephrine or carbachol showed a weak but PT-sensitive action. When any one of the latter agonists was applied to the cells treated with low doses of BK, however, the level of [Ca2+]i rise caused by the agonist was remarkably increased in a PT-sensitive manner. The decreasing of extracellular Ca2+ only slightly influenced the actions of these agonists. Thus, synergism between a BK receptor and PT-sensitive G-protein-coupled receptors results in marked intracellular Ca2+ mobilization by the latter agonists.
Department of Physical Biochemistry, Gunma University, Maebashi, Japan.
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Okajima
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Kondo
D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004357:Drug Synergism; D019204:GTP-Binding Proteins / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology; D037342:Pertussis Toxin; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism; D013004:Somatostatin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D017981:Receptors, Neurotransmitter; D010566:Virulence Factors, Bordetella; D013004:Somatostatin; D002217:Carbachol; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D001920:Bradykinin; D002118:Calcium; D009638:Norepinephrine