Effect of adding purified VWF on the platelet adhesion under flow using platelet-reduced blood. Platelet-reduced blood (4-6 × 104 platelets/μL) was prepared from PPACK-treated whole blood, added with different amounts of purified VWF or rFVIII, and perfused into the flow chamber for 2 minutes at a shear rate of 1600 s–1. (A) Platelet adhesions of platelet-reduced blood with no additions 0 (n = 11),1(n = 6),2(n = 6), or 4 (n = 5) VWF:RCo U/mL purified VWF; or 2 FVIII:C U/mL rFVIII (n = 6). Normal blood indicates the platelet adhesion of the original blood (n = 14). Data are each a mean ± SEM. *P < .05 as compared with no addition of purified VWF. (B) Photo images of the platelets adhered on collagen surface corresponding to the experiments in panel A. Those photo images were captured at 2 minutes after start of the perfusion. Magnification, × 400.
