[Simultaneous determination of effective renal plasma flow and glomerular filtration rate using a double isotope technic--determination of the filtration fraction].

A method for the simultaneous determination of the effective renal plasma flow and of the glomerular filtration rate with the help of 131J-o-iodohippuric acid and 169Yb-DTPA using a double isotopic technique is described. Apart from this the method serves for the establishment of the filtration fraction. 40 patients with different clinical pictures (glomerulonephritis, pyelonephritis, cystic kidneys, stenosis of the renal artery) were examined. The clearance values established by us were in the areas characteristic for the clinical pictures. Pathological conditions could be established which are not yet characterized by an increase of the fixa of the urine in the serum. By the determination of the filtration fraction differential-diagnostically important insights are afforded. The examination is methodically simply to be performed and is of little stress for the patient. Therefore it seems to be suitable for the routine examination.