Inhibition of cell stimulation of plasminogen activation by tranexamic acid. Plasmin generation rates for the activation of 100 nmol/L lys-plasminogen in the presence of 15 pmol/L uPA and varying cell concentrations were determined using U937 (⧫) or Nalm6 cells (•). The open symbols show results from reaction mixtures also containing 2 mmol/L tranexamic acid to block plasminogen binding to U937 cells (◊) and Nalm6 cells (○). Activation rates are shown as mean ± SE, n = 2.