Mechanical Response of the Endothelial Glycocalyx to Pulsatile Flow

Abstract

The endothelial glycocalyx is a thin layer lining the internal wall of all blood vessels. It is in the arteries wall where cholesterol and other fatty materials can accumulate eventually obstructing the blood flow and causing atherosclerosis and other vascular diseases to occur. Although the correlation between regions of this arterial disease and areas with low and disturbed wall shear stress has been established, its patterns still do not match. The glycocalyx is considered to be responsible for the transduction of the fluid-induced shear stress to biomechanical forces in the endothelium. A mechanical model of the glycocalyx as a dense matt of regularly distributed stiff rods attached to the endothelial cell membrane and subject to the wall shear stress and drag forces has been developed to study how blood flow forces are actually ‘felt’ by the arterial wall. It is found that for oscillating forces with high amplitude, compared to its average value, the frequency of the applied force is a key factor to determine the actual pulling force transferred through the fibres of the glycocalyx to the endothelium. However, the post-processing of simulated wall shear stress in a rabbit’s descending thoracic aorta with the developed mechanical model has not revealed major changes in the transduced force pattern.