Fig. 2.

Several APL molecular species are externalized by human platelets in response to agonists and are dose-dependent to thrombin. (A and B) Platelets were activated using thrombin (0.2 U/mL), collagen (10 µg/mL), or ionophore (A23187, 10 µM) at 37° for 30 min, before biotinylation, lipid extraction, and LC/MS/MS analysis as in Materials and Methods. (C and D) Total APL in each sample was determined by biotinylation using NB, as described in Materials and Methods, and used to calculate the relative proportion externalized on platelet activation. (E and F) Platelets were activated by thrombin (0.2 U/mL) for varying times, as shown, before biotinylation, lipid extraction, and LC/MS/MS analysis as in Materials and Methods (n = 3; mean ± SEM; data representative of three independent experiments. *P < 0.05, **P < 0.01, and ***P < 0.001 vs. control, using ANOVA and Bonferroni post hoc test).