title: Calcium ionophore potentiates chemotactic peptide and platelet activating factor in stimulating thromboxane B2 and leukotriene B4 biosynthesis in human neutrophils.
abstract: Formyl-Met-Leu-Phe (FMLP) and platelet activating factor (PAF) stimulated the synthesis of thromboxane B2 (TXB2) and leukotriene B4 (LTB4) to a small degree in human neutrophils. Calcium ionophore A-23187 enhanced synergistically both FMLP and PAF induced eicosanoid synthesis, whereas phorbol ester PMA attenuated PAF but not FMLP stimulated arachidonate metabolism. These results suggest that calcium mobilization may be a rate limiting step in FMLP and PAF induced synthesis of TXB2 and LTB4 and that protein kinase C activation may play a negative regulatory role in PAF stimulated eicosanoid synthesis.
authors.affiliation: Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Kentucky, Lexington 40536-0082.
authors.forename: H
authors.initials: H
authors.lastname: Tanizawa
authors.forename: H H
authors.initials: HH
authors.lastname: Tai
mesh_terms: D000001:Calcimycin / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D007975:Leukotriene B4 / Q000096:biosynthesis*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010972:Platelet Activating Factor / Q000494:pharmacology; D011863:Radioimmunoassay; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013929:Thromboxane B2 / Q000096:biosynthesis*
chemical_list: D010972:Platelet Activating Factor; D007975:Leukotriene B4; D000001:Calcimycin; D013929:Thromboxane B2; D009240:N-Formylmethionine Leucyl-Phenylalanine; D013755:Tetradecanoylphorbol Acetate