Frequency distribution of K_ex resulting from activation by different agonists. The rate constants, K_ex, were calculated as in “Methods.” The gray bars represent the frequency distribution of K_ex values obtained on stimulation of platelets with various agonists as indicated. Superimposed dashed curves represent the Gaussian functions shown in Figure 3. The number of K_ex values used in making the pdfs incorporate 43 K_ex values for thrombin (A), 19 K_ex values for PAR1-agonist (B), and 17 K_ex values for convulxin (C).