TSP-1 modulates PGE1-mediated inhibition of platelet arrest under conditions of flow. Platelets were incubated with either TSP-1 (10 μg/mL) alone for 15 minutes, PGE1 (10μM) alone for 2 minutes, or TSP-1 (10 μg/mL) for 15 minutes followed by PGE1 for 2 minutes. Platelets were recombined with autologous red blood cells, and the reconstituted blood was flowed over immobilized fibrinogen (1 mg/mL), for 2 minutes at 800s−1, and resulting platelet aggregates were viewed by fluorescent microscopy. Shown are (A) representative images from 4 independent experiments and (B) percent surface-area coverage. Data are shown as percent area coverage and are the mean ± SEM of 4 experiments. *P < .01 surface-area coverage when platelets with treated with PGE1 alone are compared with those pretreated with TSP-1 before PGE1.
