Changes in cytosolic [Ca⁺⁺]_i upon activation of G_i2α(+/G184S) platelets. (A) G_i2α(+/G184S) and matched control platelets were loaded with Fura-2 and stimulated with several concentrations of each of the indicated agonists. Ca⁺⁺-dependent Fura-2 fluorescence over time for each agonist is shown for wild-type (top) and G_i2α(+/G184S) platelets (bottom). (B) A comparison of average maximal fluorescence over the range of agonist concentrations studied for each genotype. Each curve represents the average of 8 replicates. The experiment was performed twice with similar results obtained. Blood obtained from 2 mice of each genotype was used for each experiment.