The requirement of the PKC signaling pathway for L5-mediated platelet activation. (A) L5 (25 or 50 μg/mL) increased PKCα phosphorylation in platelets in a dose-dependent manner. (B) L5 (25 or 50 μg/mL) alone induced Akt activation in a dose-dependent manner. (C) L5 (25 μg/mL) augmented ADP-induced (4 μM ADP) Akt phosphorylation. (D) L5 (25 or 50 μg/mL) decreased the expression of cAMP in platelets. Flow cytometry analysis of platelets, treated as indicated, showing the number of cells in which (E) P-selectin is expressed and (F) GPIIb/IIIa is activated, expressed as a ratio to that of the PBS-treated control (Ctl) group. All data shown represent the mean ± standard deviation; *P < .05; **P < .01; ***P < .001 vs PBS-treated control (n = 5), determined by using 1-way analysis of variance with the Bonferroni post hoc test.