The impact of blood rheology on the molecular and cellular events underlying arterial thrombosis.

There is an increasing appreciation of the importance of disturbed blood flow, especially turbulent flow, in the pathogenesis of vascular disease. However, the precise mechanism(s) by which rheological changes accelerate the atherothrombotic process remains incompletely understood. Atherosclerotic lesions typically develop in vascular regions exhibiting bifurcated or curved architectures. Such regions exhibit complex blood flow profiles with considerable divergence from uniform laminar flow. These altered flow behaviours can promote deposition of pro-atherogenic lipids and proteins to the vessel wall and modulate the adhesive function of endothelial, platelets and leukocytes. Once developed, atherosclerotic lesions can further exacerbate flow disturbances, establishing a potential hazardous cycle of accelerated atherogenesis. At the cellular level, alterations in fluid flow can lead to significant changes in signal transduction, leading to a variety of functional and morphological changes. In particular, disturbed rheology has a significant impact on the adhesion and activation mechanisms utilised by platelets and leukocytes with high shear, playing an important role in accelerating platelet activation and thrombus growth. This review focuses on the impact of blood rheology on the cellular and molecular events underlying thrombosis, with particular emphasis on the role of platelets in this process.