title: Inhibition of histamine release from human basophils in vitro by calmodulin antagonists.
abstract: Calmodulin is a ubiquitous and versatile Ca2+-binding protein that plays a pivoting role in cellular metabolism. We have investigated the possibility that calmodulin plays a role in immediate hypersensitivity reactions by evaluating the effects of two agents, trifluoperazine dihydrochloride (TFP) and the sulfonamide derivative N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) which selectively bind to calmodulin. TFP and W-7 cause a dose-dependent inhibition of histamine secretion from human basophils in vitro induced by several immunological (i.e., antigen and anti-IgE) and nonimmunological (i.e., formyl-methionine-containing peptide and the Ca2+ ionophore A23187) stimuli. These results indicating that two specific calmodulin antagonists are potent inhibitors of the secretory response of human basophils support the hypothesis that calmodulin may play a role in the control of the release of preformed mediators from human inflammatory cells.
mesh_terms: D000328:Adult; D001491:Basophils / Q000187:drug effects* / Q000276:immunology; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D004305:Dose-Response Relationship, Drug; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D007166:Immunosuppressive Agents; D013449:Sulfonamides; D014268:Trifluoperazine; C017967:W 7