Comparison of the renal hemodynamic response to unilateral and bilateral ureteral occlusion

The renal hemodynamic response to 24 hr of unilateral and bilateral ureteral occlusion was studied in female dogs. The renal blood flow rose initially and then decreased to be significantly below postobstruction levels in both models. After 24 hr, the ureteral pressure was elevated in bilateral ureteral obstruction but was near control levels in unilateral ureteral obstruction, implying increased preglomerular vascular resistance in unilateral ureteral obstruction and increased postglomerular vascular resistance in bilateral ureteral obstruction.