The influence of antagonists of collagen receptors and integrin α
in brazilin-mediated platelet aggregation. Washed platelets (3.6 × 108/ml) were preincubated with JAQ1 (4 μg/ml), Sam.G4 (4 μg/ml), U73122 (10 μM), indomethacin (25 μM), or caffeic acid phenethyl ester (CAPE; 25 and 50 μM). This was followed by the addition of (A and C-E) collagen (1 μg/ml), (B) thrombin (0.5 U/ml), or (C-F) brazilin (50 μM) to trigger platelet aggregation. (G) The solid line represents the fluorescence profiles of FITC-triflavin (a) in the absence of brazilin as a positive control; (b) in the presence of 5 mM EDTA as a negative control; (c) in the presence of 25 μM brazilin; or (d) in the presence of 50 μM brazilin. Thereafter, 2 μg/ml FITC-triflavin was added in each case. Profiles (A to G) are representative examples of 4 similar experiments.