Effects of DCB, bepridil or Ro31-8220 on platelet aggregation. Washed platelet suspended in modified Tyrode Hepes buffer containing 1 mmol/L CaCl ₂ were stimulated by indicated agonists (0.1 U/mL thrombin, 20 μmol/L ADP, 200 nmol/L PMA and 1 μmol/L A23187) in the presence (indicated dose; μmol/L) or absence (indicated as “0”) of each indicated inhibitor under stirring conditions.