Fig. 4.

Impaired long-term Ca²⁺ responses and PS exposure in activated Glanzmann platelets. Suspensions of Fura-2-loaded platelets containing apyrase from two Glanzmann patients (1, 2) were pretreated with vehicle or tirofiban (1 μg/mL). Platelets were then activated with thrombin (10 nM) plus convulxin (50 ng/mL) in the presence of 1 mM CaCl₂. a Representative traces of Ca²⁺ responses. b Averaged Ca²⁺ peak levels (light gray) and 15-min end levels (dark gray). c Fractions of PS-exposing platelets after 15 min, showing no effect of tirofiban. Mean ± SEM (n = 3 experiments)