title: Ca2+ release and Ca2+ influx in Chinese hamster ovary cells expressing the cloned mouse B2 bradykinin receptor: tyrosine kinase inhibitor-sensitive and- insensitive processes.
abstract: A cDNA encoding a mouse B2 bradykinin (BK) receptor was stably transfected in Chinese hamster ovary (CHO) cells. In two resulting transformants, mouse B2 BK receptor was found to induce a twofold elevation in the inositol-1,4,5-trisphosphate level. In a pertussis toxin-insensitive manner, BK also produced a biphasic increase in the intracellular Ca2+ concentration ([Ca2+]i). The initial elevation in [Ca2+]i was abolished by thapsigargin pretreatment in Ca(2+)-free medium. The second phase was dependent on external Ca2+. The BK/inositol trisphosphate and thapsigargin-sensitive Ca2+ stores required extracellular Ca2+ for refilling. Ca2+ influx induced by BK and thapsigargin was confirmed by Mn2+ entry through Ca2+ influx pathways producing Mn2+ quenching. Genistein, a tyrosine kinase inhibitor, partially decreased the BK-induced [Ca2+]i increase during the sustained phase and the rate of Mn2+ entry. BK had essentially no effect on the intracellular cyclic AMP level. The results suggest that the mouse B2 BK receptor couples to phospholipase C in CHO cells and that its activation results in biphasic [Ca2+]i increases, by mobilization of intracellular Ca2+ and store-depletion-mediated Ca2+ influx, the latter of which is tyrosine phosphorylation dependent.
authors.affiliation: Department of Biophysics, Kanazawa University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Taketo
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Y
authors.initials: Y
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Higashida
mesh_terms: D000818:Animals; D001665:Binding Sites; D001920:Bradykinin / Q000378:metabolism / Q000494:pharmacology; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism*; D003001:Cloning, Molecular; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein; D006706:Homeostasis; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007529:Isoflavones / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin / Q000235:genetics / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology; D014162:Transfection
chemical_list: D004791:Enzyme Inhibitors; D007529:Isoflavones; D043782:Receptor, Bradykinin B2; D018002:Receptors, Bradykinin; D019000:Phosphotyrosine; D008345:Manganese; D019284:Thapsigargin; D015544:Inositol 1,4,5-Trisphosphate; D019833:Genistein; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases; D001920:Bradykinin; D002118:Calcium