The effect of genistein on thrombin-induced endothelial permeability is independent of ERs or PTK. A, BAEC monolayers were preincubated with or without (C) ICI 182,780 (I) for 30 minutes, then with the presence of 5 μM genistein (G) for 30 minutes, followed by addition of 2 U/ml thrombin (T) for 1 hour. B, BAEC monolayers were pretreated with 5 μM genistein (G) or daidzein (D) for 30 minutes prior to addition of 2 U/ml thrombin (T) for 1 hour. Avidin-FITC passage was measured, and data are expressed as mean ± SE of three different experiments, each performed in duplicate. *P < .05 vs control; †P < .05 vs thrombin-alone-treated cells.