title: Evaluation of effects of various drugs on platelet functions using phorbol 12-myristate 13-acetate-induced megakaryocytic human erythroid leukemia cells.
abstract: BACKGROUND
  The hyperfunction and activation of platelets have been strongly implicated in the development and recurrence of arterial occlusive disease, and various antiplatelet drugs are used to treat and prevent such diseases. New antiplatelet drugs and many other drugs have been developed, but some drugs may have adverse effects on platelet functions.
  
  
  OBJECTIVE
  The aim of this study was to establish an evaluation method for evaluating the effect and adverse effect of various drugs on platelet functions.
  
  
  METHODS
  Human erythroid leukemia (HEL) cells were used after megakaryocytic differentiation with phorbol 12-myristate 13-acetate as an alternative to platelets. Drugs were evaluated by changes in intracellular Ca2+concentration ([Ca2+]i) mobilization in Fura2-loaded phorbol 12-myristate 13-acetate-induced HEL cells. Aspirin and cilostazol were selected as antiplatelet drugs and ibuprofen and sodium valproate as other drugs.
  
  
  RESULTS
  There was a positive correlation between [Ca2+]iand platelet aggregation induced by thrombin. Aspirin (5.6-560 µM) and cilostazol (5-10 µM) significantly inhibited thrombin-induced increases in [Ca2+]iin a concentration-dependent manner. On the other hand, ibuprofen (8-200 µM) and sodium valproate (50-1,000 µg/mL) also significantly inhibited thrombin-induced increases in [Ca2+]iin a concentration-dependent manner. Furthermore, the interaction effects of the simultaneous combined use of aspirin and ibuprofen or sodium valproate were evaluated. When the inhibitory effect of aspirin was higher than that of ibuprofen, the effect of aspirin was reduced, whereas when the inhibitory effect of aspirin was lower than that of ibuprofen, the effect of ibuprofen was reduced. The combination of aspirin and sodium valproate synergistically inhibited thrombin-induced [Ca2+]i.
  
  
  CONCLUSIONS
  It is possible to induce HEL cells to differentiate into megakaryocytes, which are a useful model for the study of platelet functions, and the quantification of the inhibition of thrombin-induced increases in [Ca2+]iis applicable to the evaluation of the effects of various drugs on platelets.
authors.affiliation: Subdivision of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Tokushima University.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Tada
authors.affiliation: Department of Cells and Immunity Analytics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima.
authors.forename: Kensaku
authors.initials: K
authors.lastname: Aki
authors.affiliation: Subdivision of Biomedical Laboratory Sciences, Graduate School of Health Sciences, Tokushima University; Department of Medical Technology, Kagawa Prefectural University of Health Sciences, Kagawa.
authors.forename: Wataru
authors.initials: W
authors.lastname: Oboshi
authors.affiliation: Department of Clinical Pharmacy Practice Pedagogy, Institute of Biomedical Sciences.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Kawazoe
authors.affiliation: Department of Reproductive and Menopausal Medicine, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yasui
authors.affiliation: Department of Cells and Immunity Analytics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima.
authors.forename: Eiji
authors.initials: E
authors.lastname: Hosoi
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects*; D000077407:Cilostazol; D006801:Humans; D008533:Megakaryocytes / Q000187:drug effects*; D010703:Phorbol Esters / Q000494:pharmacology*; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D010979:Platelet Function Tests; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013777:Tetrazoles / Q000494:pharmacology*
chemical_list: D010703:Phorbol Esters; D010975:Platelet Aggregation Inhibitors; D013777:Tetrazoles; C119222:phorbol-12-myristate; D000077407:Cilostazol; D013755:Tetradecanoylphorbol Acetate; D001241:Aspirin
keywords: aspirin; cilostazol; ibuprofen; intracellular Ca2+ concentration ([Ca2+]i); platelets; sodium valproate