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Updated: Jun 23, 2026

A Uniform Shear Assay for Human Platelet and Cell Surface Receptors via Cone-plate Viscometry
Published on: June 5, 2019
Exercise-induced shear stress is associated with changes in plasma von Willebrand factor in older humans
Joaquin U Gonzales1, John R Thistlethwaite, Benjamin C Thompson
1Cardiopulmonary and Metabolism Research Laboratory, Department of Kinesiology, The University of Toledo, Toledo, OH 43606, USA.
Abstract:
Shear stress is the frictional force of blood against the endothelium, a stimulus for endothelial activation and the release of von Willebrand factor (vWF). This study tested the hypothesis that the increase in shear stress associated with exercise correlates with plasma vWF. Young (n = 14, 25.7 +/- 5.4 years) and older (n = 13, 65.6 +/- 10.7 years) individuals participated in 30 min of dynamic handgrip exercise at a moderate intensity. Brachial artery diameter and blood flow were measured using ultrasound Doppler and blood samples were collected before, immediately after, and following 30 min of recovery from exercise with plasma levels of vWF. Plasma levels of vWF increased (P < 0.05) by 6 +/- 2% in young individuals and 4 +/- 1% in older individuals immediately after exercise. The change in plasma vWF was linearly correlated with the increase in shear stress during exercise in older individuals (post-exercise: r = 0.78, 30 min recovery: r = 0.77, P < 0.01), but no association was found in the young individuals. These changes in plasma levels of vWF in humans suggest that aging influences endothelial activation and hemostasis.
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