Single Proximal Tubules of the Necturus Kidney. II. Effect of 2,4-Dinitrophenol and Ouabain on Water Reabsorption

Abstract

The effect of ouabain and 2,4-dinitrophenol on water reabsorption from the proximal tubule of the kidney of Necturus maculosus has been studied using the collection and stopped flow perfusion techniques previously described. The intravenous administration of ouabain in collection experiments results in a decrease in water reabsorption from 32.7% (normal controls) to 15.4%. In stopped flow perfusion experiments on control animals, water reabsorption after 20 minutes is 27.2%. When 2,4-dinitrophenol or ouabain is added to the perfusion fluids, values of 10.2% and 9.8%, respectively, are observed. The experimental findings demonstrate that water reabsorption in the proximal tubule is inhibited by these agents. The results are in agreement with the hypothesis of active reabsorption of sodium from the proximal tubule of the kidney of Necturus.