Fig. 4. Effect of C3 Transferase on PAR-mediated dense granule secretion in human platelets.
Aspirin-treated and washed human platelets were stimulated with 500 μM AYPGKF, 10 μM SFLLRN or 0.2 U/ml Thrombin at 37°C while stirring. Platelet samples were incubated with 20 μg/ml exoenzyme C3 Transferase at 37°C for 4 hrs before the addition of agonists. Platelet shape change (A) aggregation (B) and secretion (C and D) were measured in a Lumi aggregometer. The tracings are representative of data from at least three independent experiments. The secretion data in panel D were normalized to the maximum secretion (taken as 100%).