Pharmacological Characterization of Inositol 1,4,5-tris Phosphate Receptors in Human Platelet Membranes
Figure 4
Displacement curve for the inhibition of [3H]Ins(1,4,5)P3 binding to human platelet membranes by inositol phosphates. Platelet membranes were incubated with 20 nM [3H]Ins(1,4,5)P3 in the presence of increasing concentrations of D-Ins(1,4,5)P3 (▲), D-Ins(2,4,5)P3 (●), GPIP2 (♦), and L-Ins(1,4,5)P3 (■) at 4°C for 10 minutes. The data are the mean S.E.M. of three independent experiments, each run in duplicate. The IC50 values were calculated using the displacement curve (Table 1).