A complex flow pattern of low shear stress and flow reversal promotes monocyte binding to endothelial cells.

Predilection sites for atherosclerosis within the vasculature are characterized by low shear stress and flow reversal. In this study, endothelial cells were exposed to a complex flow pattern that was characterized by particle velocity determination. Bovine aortic endothelial cells exposed to low shear stress and flow reversal demonstrated higher levels of monocyte binding compared to endothelial cells exposed to one-directional flow. In addition, endothelial cells exposed to low shear stress and flow reversal responded to inflammatory stimuli with substantial increases in monocyte binding, similar to that seen in cells exposed to one-directional flow. These findings suggest a mechanism by which areas of low shear stress and flow reversal are predisposed to the development of atherosclerotic lesions.