Improved Sodium and PAH Transport in the Isolated Fluorocarbon-Perfused Rat Kidney

Abstract

The effect of an artificial O₂ carrier (emulsion of the perfluorochemical FC43® with Pluronic-F-108®) on the functional capability of the isolated perfused rat kidney was tested. In control series hydroxyethyl starch (HES) instead of fluorocarbon was used. Improving O₂ supply in FC 43 experiments raised Na reabsorption to 149 µmol/g × min compared to 84.1 µmol/g × min in HES experiments. In the presence of PAH, however, Na reabsorption in FC 43 experiments was only 115 µmol/g × min. In both series, perfusion flow, calculated on the basis of Cpah, remained below the directly measured flow rate, unless analysis included all metabolites of PAH. 7V-acetylated metabolites of PAH were released at a 5 times higher rate by kidneys perfused with FC 43 than by HES-perfused organs. These results demonstrate that sufficient O₂ supply is critical both for reabsorption of Na+ and for handling of PAH. Increased tubular Na reabsorption in the absence of PAH indicates that even during perfusion with FC 43 O₂ supply is marginal.