Abstract
We have reported that the 1.8% paraformaldehyde-fixed and lyophilized human platelets retained surface Glycoprotein Ib with functional, and that may be one of the candidates as platelets substitute. In this paper, we focused on fibrinogen receptor, glycoprotein IIb/IIIa (GP Ilb/IIIa) on plasma membrane which is essential for hemostasis. To maintain GP IIb/IIIa with fibrinogen-binding activity, we activated fresh human platelets with ADP and subsequently fixed with 2 % paraformaldehyde. Aggregation analysis and flowcytometric analysis demonstrated that ADP activated, lyophilized and rehydrated platelets possessed not only ristocetin-dependent aggregation but fibrinogen-binding activity on platelet surface. These results indicate that ADP-activated and lyophilized platelets retain not only functional GP Ib but also surface GP IIb/IIIa in an activated form. This study suggest that ADP-activated and lyophilized platelets may effectively stop bleeding in patients with thrombocytepenia, and may be useful as a platelet substitute.
