title: Ionomycin induces prostaglandin E2 formation in murine osteoblastic MC3T3-E1 cells via mechanisms independent of its ionophoric nature.
abstract: Ionomycin and A23187 are divalent cation ionophores with a marked preference for calcium. Studies using these ionophores have almost exclusively interpreted their results in the light of calcium elevation. It was the aim of this study to investigate the effects of ionomycin in osteoblatic MC3T3-E1 cells that are not attributable to its ionophoric properties. Thus, we have found that in contrast to A23187, ionomycin shows similar effects on prostaglandin E2 formation as bradykinin and endothelin-1, being potentiated by extracellular nickel and inhibited by cholera toxin and pertussis toxin. Our data strongly suggest that inomycin, at least in part, exerts its effects via specific binding to a G-protein coupled receptor, thereby evoking downstream cellular events like arachidonate release with subsequent prostaglandin formation.
authors.affiliation: University Hospital of Youth and Adolescence Medicine, Medical University of Graz, Research Unit of Analytical Mass Spectrometry, Cell Biology and Biochemistry of Inborn Errors of Metabolism, Auenbruggerplatz 34/2, A-8036 Graz, Austria.|University Hospital of Youth and Adolescence Medicine, Medical University of Graz, Research Unit of Analytical Mass Spectrometry, Cell Biology and Biochemistry of Inborn Errors of Metabolism, Auenbruggerplatz 34/2, A-8036 Graz, Austria.
authors.forename: Hans Jörg
authors.initials: HJ
authors.lastname: Leis
authors.affiliation: University Hospital of Youth and Adolescence Medicine, Medical University of Graz, Research Unit of Analytical Mass Spectrometry, Cell Biology and Biochemistry of Inborn Errors of Metabolism, Auenbruggerplatz 34/2, A-8036 Graz, Austria.|University Hospital of Youth and Adolescence Medicine, Medical University of Graz, Research Unit of Analytical Mass Spectrometry, Cell Biology and Biochemistry of Inborn Errors of Metabolism, Auenbruggerplatz 34/2, A-8036 Graz, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Windischhofer
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D061207:Calcium Ionophores / Q000494:pharmacology; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D015232:Dinoprostone / Q000096:biosynthesis / Q000378:metabolism*; D015759:Ionomycin / Q000494:pharmacology*; D051379:Mice; D009532:Nickel / Q000494:pharmacology; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism
chemical_list: D061207:Calcium Ionophores; D043562:Receptors, G-Protein-Coupled; D000001:Calcimycin; D015759:Ionomycin; D009532:Nickel; D002772:Cholera Toxin; D037342:Pertussis Toxin; D015232:Dinoprostone; D001920:Bradykinin; D002118:Calcium
keywords: A23187; MC3T3-E1; and MC3T3-E1; ionomycin; ionomycine; nickel; osteoblast; ostéoblaste; prostaglandin; prostaglandine