PAR-1 density influences the platelet response to SFLLRN.

(A) The SFLLRN concentration causing a double wave of aggregation (x-axis) correlated negatively with PAR-1 density (ordinate;r² = 23%, P < .001). The mean value of the 2 determinations 1 week apart is plotted for each variable. (B) Platelet secretion in response to 100 μM SFLLRN (P-selectin expression, x-axis) correlated with PAR-1 density (y-axis;r² = 30%, P < .001). The mean value of the 2 determinations 1 week apart is plotted for each variable. (C) Platelet secretion in response to 100 μg/mL collagen stimulation (P-selectin expression, x-axis) did not correlate with PAR-1 density (y-axis; P = .28).