Computational study of endothelial-mediated vascular responses at Y-bifurcation: when occlusion does not reduce the total ow

摘要

The patterns of ow distribution in the microcirculation network are rather well studied in the hydrodynamicapproximation. Similarly, a signicant amount of results are available on the cellular mechanisms of autoregu-lation of vascular tone in a single vessel. However, the situation when autoregulation changes the distributionof ows in response to any changes in conditions is much less studied. In this paper, we explore the dynamicrestructuring of the state of the smallest microcirculatory network, consisting of only 3 segments. Such a networkarises around a simple branching (Y-bifurcation) of blood vessels. Using a mathematical model of a vessel seg-ment, which takes into account two main mechanisms of autoregulation, we show the possibility of a paradoxicalreaction of the general ow to the occlusion of one of the segments. Our analysis shows that the found eectis based on the instability of the state caused by the presence of positive feedback, which, in turn, occurs whenthe endothelial layer of the vessel responds to the shear stress caused by friction forces between the endotheliumcells and the blood ow.