Thromb Haemost 2008; 100(01): 60-68
DOI: 10.1160/TH07-03-0222
Platelets and Blood Cells
Schattauer GmbH

Effects of von Willebrand factor concentration and platelet collision on shear-induced platelet activation

Zhenyue Gao
1   Bioengineering Department of Beijing University of Aeronautics and Astronautics, Beijing, China
,
Fang Liu
2   Jiangsu Institute of Hematology, Suzhou, China
,
Ziqiang Yu
2   Jiangsu Institute of Hematology, Suzhou, China
,
Xia Bai
2   Jiangsu Institute of Hematology, Suzhou, China
,
Chun Yang
1   Bioengineering Department of Beijing University of Aeronautics and Astronautics, Beijing, China
,
Fengyuan Zhuang
1   Bioengineering Department of Beijing University of Aeronautics and Astronautics, Beijing, China
,
Changgeng Ruan
2   Jiangsu Institute of Hematology, Suzhou, China
› Author Affiliations

Financial support: This work was supported by a grant from the National Natural Sciences Foundation of PR China (No. 10402002 and 30670904), and a Foundation for the Author of National Excellent Doctoral Dissertation of PR China (No. 200356).
Further Information

Publication History

Received 26 March 2007

Accepted after major revision 06 May 2008

Publication Date:
22 November 2017 (online)

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Summary

The binding of plasma von Willebrand factor (vWF) to platelet glycoprotein (GP) Ibα in a high shear stress field, and subsequent integrin-GPIIb/IIIa-vWF conjunction induces platelet aggregation (SIPA). However, the specific biomechanical mechanism of the vWF-GPIb interaction still remains to be elucidated. A parallel-plate rectangular flow chamber was built to simulate a stenopeic artery flow pattern. Using the flow chamber, we examined shear- induced platelet activation (SIPAct) at different vWF concentrations (5–25 µg/ml) and several simulated stenotic high shear rates. P-selectin expression on the platelets and annexin V binding to the platelets were used as two markers of platelet activation. At different localized shear rates (3,000 s-1–9,500 s-1), the percentage of annexin V and P-selectin positive cells increased from 8.3 ± 0.4% to 22.3 ± 1.8% ( p 0.05) and from 17.4 ± 0.5% to 33.5 ± 2.5% (p 0.05),respectively. As the vWF concentration increased from 5 µg/ml to 25 µg/ml, the annexinV binding rate increased from 7.2 ± 0.6% to 53.4 ± 3.8% (p 0.05), and P-selectin expression increased from 16.5 ± 1.2% to 65.9 ± 5.2% (p 0.05). A test in a uniform shear field using cone-plate viscometer rheometry showed that the platelet activation rate was proportional to the platelet concentration. This result suggests that platelet collision is one of the impact factors of SIPAct.