Figure 2: Effect of tryptase on the VEGF, Flt-1, and Flk-1 protein levels in HDMECs with or without APC366. HDMECs were treated with different concentrations of tryptase for 18 h in the absence or presence of APC366 (250 μg/mL). The protein levels of VEGF (a), Flt-1 (b), and Flk-1 (c) were determined by Western blot and normalized to GAPDH. The heparin control was also analyzed. compared to the group of nonaddition. compared to the group only treated with tryptase at the same concentration.