Time course of TF activity expression on HUVECs stimulated with TNF, thrombin, or PMA and the effect of dilazep on the TF expression. HUVECs (5 × 10⁵/well) were stimulated with (A) 1,000 U/mL TNF, (B) 25 nmol/L thrombin, or (C) 5 nmol/L PMA in the presence (•) or absence (○) of 100 μg/mL dilazep. The TF activity on HUVEC surface was determined at 0, 3, 5, 6, 9, 12, and 24 hours after incubation with each stimulant as factor Xa generation (A_405nm /20 minutes) using S2222 (see the Materials and Methods). The values represent the mean ± SD of four independent experiments.