Effect of Dex on anti–GPIIIa-49-66 Ab– or Ca²⁺ ionophore–induced intracellular Ca²⁺ flux. Control or patient IgG (25 μg/mL) was added to fura-2 AM–loaded gel-filtered platelets and fluorescence monitored for 20 minutes. Ca²⁺ flux was determined from fluorescence ratios following excitations at 340 and 380 nm and fluorescence detection at 510 nm. (A) Control. (B) Anti–GPIIIa49-66. (C) Ab + Dex. (D) Ca²⁺ ionophore. (E) Ca²⁺ ionophore + Dex (n=3).