Cytochalasin D specifically enhances vWf-induced platelet aggregation.

Washed platelets (3 × 10⁸/mL) were incubated with either vehicle alone (−) or 5 μmol/L CD (+) prior to the initiation of platelet aggregation with the indicated concentrations of thrombin (A), collagen (B), ADP (C), HvWf (0.5 μg/mL) and ristocetin (1 mg/mL), or BvWf (1 μg/mL). These aggregation tracings are from 1 experiment, representative of 5. The accompanying bar graph is a quantitative representation of the effects of CD on the rate of platelet aggregation induced by low concentrations of the indicated agonist. Results are presented as the fold increase in the initial rate of aggregation relative to Me₂SO-treated platelets. Results are the mean ± SE from 5 experiments.