Figure 5. α_IIb-Tg-hPAR1 transgenic mice on a PAR4^−/− background do not respond to thrombin.

(A) Intracellular calcium mobilization was measured in platelets from α_IIb-Tg-hPAR1-PAR4^−/− mice in response to thrombin (10 nM). The tracing is representative of three independent experiments. (B) P-selectin expression was measured in the surface of platelets from wild type (wt) (gray bars) or α_IIb-Tg-hPAR1-PAR4^−/− (white bars) mice by flow cytometry using FITC conjugated P-selectin antibody in response to thrombin (10 nM) or SFLLRN (30 µM). (C) Platelets were treated as in (B) and integrin αIIbβ3 activation was measured using PE conjugated JON/A antibody. The results are the mean of three independent experiments.