Aggregation induced by 4N1-1 is partly mediated by αIIbβ3.

(A) Human platelets were pretreated for 10 minutes with 1 mM Arg-Gly-Asp-Ser, 40 μM BAPTA-AM, 10 μM PP1, or a combination of these inhibitors before stimulation with 25 μM 4N1-1. (B) Platelets from patients with type I Glanzmann thrombasthenia (GT) or control donors (c) were pretreated, when necessary, for 10 minutes with 10 μM PP1 before stimulation with 25 μM 4N1-1, 0.5 μg/mL convulxin, 0.1 U/mL thrombin, or 10 μg/mL vWF activated with 1 mg/mL ristocetin. Aggregation was monitored by light transmission. Arrows indicate addition of agonist. Results are representative of experiments using platelets from 3 different control donors and one patient with GT.