Effect of Increased Ureteral Pressure on Renal Function

Abstract

Ureteral pressure was acutely increased to 15, 20, 25 or 30 mm. Hg in anesthetized dogs. A ureteral pressure of 15 mm. Hg had no apparent effect on renal function, while the higher pressures produced changes which were qualitatively similar. Glomerular filtration rate, generally renal plasma flow and frequently filtration fraction were reduced. There was a tendency for both glomerular filtration rate and renal plasma flow to return toward control levels in the 2d of the 2 periods of increased ureteral pressure. Na excretion and urine flow were markedly reduced, and these changes were accompanied by an increase in the percentage tubular reabsorption of Na and water. When glomerular filtration rate returned toward control in the 2d pressure period, there was no corresponding increase in urine flow or Na excretion. K excretion was also reduced by the elevated ureteral pressure but not to the same extent as were Na and water excretion. The mechanisms involved in these changes in renal function are discussed.