Experiments have been designed to study tubular function by analysis of renal tissue under conditions of oliguria and mannitol diuresis. A 50-min ureteral obstruction of one kidney was induced by forcing previously excreted urine into the renal pelvis. Without releasing the obstruction, the experimental and control kidneys were removed simultaneously. Relationships between tissue concentration and tubular function have been demonstrated. Substances that are reabsorbed in medulla accumulate in its interstitium during free flow, and this accumulation is reduced by ureteral obstruction. Persistent filtration during stop flow is manifested by accumulation of creatinine throughout the kidney, and is attributed to a distal leak induced by sodium reabsorption. Accumulation of PAH in cortex is enhanced by ureteral obstruction in mannitol diuresis, but the localized effect on PAH is obscured by high levels of persistent filtration in oliguria. The maintenance of phosphorus and potassium levels during stop flow is attributed to their high intracellular concentrations.
Spontaneous rupture of renal pelvis secondary to ureteral obstruction by urothelial tumor