On the mechanism of angiotensin-induced proteinuria. I. Studies in aminonucleoside nephrotic rats and in saralasin blockade.

To test whether angiotensin (AII) induces proteinuria via its effect on renal hemodynamics, or by another mechanism, two experimental approaches were used. In the first, it was found that AII was as effective in inducing proteinuria in nephrotic as in intact rats. In all AII augmented proteinurias, filtration fraction was increased. These effects plus electrophoretic profiles of AII proteinuria in intact rats suggested that hemodynamic changes underly the increased glomerular permeability to protein. In the second approach, the AII inhibitor, sar-ala-angiotensin, does not itself induce proteinuria or changes in GFR and RPF, but prevented the hemodynamic responses to AII and the proteinuric response as well.