Numerical solutions of differential equations for renal concentrating mechanism in inner medullary vasa recta models

Two vasa recta models of the renal concentrating mechanism are presented. It is shown that by considering the effects of ascending vasa recta permeabilities, interstitial resistance, lateral small scale histotopography, and standard deviations in permeability values, these models lead to significant improvements in collecting duct urea and salt concentration ratios.