Proximal tubular function in human hydronephrotic kidneys.

Proximal tubular was evaluated on the basis of the excretion rate of urinary beta-2-microglobulin of each kidney in 15 patients with unilateral hydronephrosis. Total and divided renal function was measured with 51chromium ethylenediaminetetraacetic acid clearance, isotope renography and a concentration test. Total renal function was normal in all patients. Parenchymal function, measured by renography, was reduced in 2 hydronephrotic kidneys and both patients had had upper urinary tract infections. The ability to concentrate urine was impaired in 10 hydronephrotic kidneys. These patients had renal calculi or had had upper urinary tract infections. The urinary beta-2-microglobulin excretion was normal in all hydronephrotic kidneys, indicating an intact proximal tubular function in these patients.