Non-isopeptide-selective endothelin receptors in human Girardi heart cells.
We characterized the endothelin (ET) receptor in Girardi heart (GH) cells derived from human atrium. The ET isopeptides ET-1, ET-2 and ET-3 induced the monotonous and long-lasting rise in cytosolic free Ca2+ concentration [( Ca2+]i) with almost the same potency in GH cells. Scatchard analysis of [125I]ET-1 and [125I]ET-3 binding revealed that GH cells have almost the same number of binding sites for either labeled ligand. All ET isopeptides displaced either [125I]ET-1 or [125I]ET-3 binding in GH cells almost equipotently. These results reveal that the functional ET receptors in GH cells are of the ETB-type. GH cells are the first cell line to be found to express the functional ETB-receptor.
Mihara
S
S
Shionogi Research Laboratories, Shionogi & Co., Ltd. Osaka, Japan.
Fujimoto
M
M
D001345:Autoradiography; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D016232:Endothelins / Q000378:metabolism*; D016257:Fura-2; D006325:Heart Atria / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D008970:Molecular Weight; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017466:Receptors, Endothelin
D003432:Cross-Linking Reagents; D016232:Endothelins; D011956:Receptors, Cell Surface; D017466:Receptors, Endothelin; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium; D016257:Fura-2