Separate Renal Function in Man Determined by a Combined Procedure Using a Dye-Dilution Method and Radioisotopes

Abstract

An investigation of separate renal function was carried out with the aid of a simultaneous determination of the renal blood flow and the extraction ratio of suitable test substances. Renal blood flow was determined by a dye-dilution method. ⁵¹Cr-EDTA was used to measure the glomerular filtration rate and ¹²⁵I-hippuran to determine the effective renal plasma flow. Apart from a simpler analytical procedure, the radioactive test substances allowed greater accuracy in the determinations than does analysis of inulin and PAH. To check the method, the clearance values calculated from studies of blood alone were compared with those obtained in the conventional manner from blood plus urine. Agreement between the methods was good.