Toward a full-scale model of renal hemodynamics using a reconstructed vascular tree.

Abstract

The kidney's vascular network stands out because 1) the microcirculation not only supplies the tissues with oxygen and nutrients but also supports glomerular filtration in each nephron, 2) it contains the tubuloglomerular feedback, a mechanism that contributes to renal blood flow autoregulation and is unique to the kidney, and 3) the topology of the renal arterial network influences signaling along the vessels mediating nephron-nephron interactions. We have developed a full-scale vascular model of the rat kidney based on a reconstructed vascular network combined with a nephron model that includes glomerular filtration, tubular reabsorption, and autoregulation of afferent arteriolar resistances. The model evaluates the steady-state operating conditions of approximately 30,000 nephrons in a rat kidney and the efficiency of autoregulation under normal and pathological conditions. The simulation results show how the regulated afferent arteriolar resistances stabilize blood flow in the reconstructed full-scale renal vascular network. It is concluded that by using a reconstructed renal vascular tree, it is possible to develop a realistic full-scale model of the regulation of renal hemodynamics as a first step toward creating a virtual kidney.NEW & NOTEWORTHY We have developed the first full-scale steady-state model integrating a realistic vascular network topology of the kidney and its hemodynamic regulatory mechanisms. The vascular network is combined with approximately 30,000 nephron models that include glomerular filtration, tubular reabsorption, and autoregulation of the afferent arteriolar resistances. By simulating the adaptive properties of the renal microcirculation at steady state, our approach demonstrates the feasibility of utilizing a reconstructed vascular network for comprehensive modeling of renal function.