Identification of shear stress as a potential vasoconduction signal across microvascular networks

The objective of this study was to computationally estimate the effects of vessel specific vasoconstriction on immediate shear stress changes across microvascular networks. Shear stress due to microvascular blood flow is an established initiator of ion-mediated signaling along microvessels which regulates control of microcirculatory blood flow. Yet, beyond initiating local vasomotion in a vessel, shear stress as a vasoconduction signal itself and characteristics of hydrodynamic propagation via blood flow are not well understood. In the current work, we use images of mesenteric microvascular networks from adult rat tissues and a network segmental blood flow model to simulate various vessel constriction scenarios and estimate subsequent shear stress changes and distances these changes spread from the site of constriction. Scenarios involving both arteriolar constriction and capillary constriction are considered, in addition to a microvascular network from muscle tissue. The findings generally reveal heterogenous and physiologically relevant shear stress changes across the networks for all cases, with magnitudes spanning a wide range and can exceed 30 dyne/cm². Further, physiological relevant wall shear changes were predicted at distances several mm from the stimulus site. Spatial patterns of shear stress change relative to network topology and capillary density are also identified. Altogether, the results invigorate consideration and discussion about shear stress as a potential player in vasoconduction responses.