[The evaluation of renal tolerance for roentgen contrast media by determination of urinary kidney-specific proteins].

In the present trial kidney-specific proteins were studied enzymatically or quantitatively in patients' urine after intravascular administration of water-soluble X-ray contrast media, in order to judge about their renal tolerance. 5 clinical trials (phase III), including 198 patients, were carried through, within several radiological examinations. The examined X-ray substance was Iosimide, a new monomeric, nonionic low osmolar c.m. It was compared to the nonionic Iopromide and Iopamidol as well as to the ionic, high osmolar sodium-meglumine-diatrizoate. Enzyme activities of alanine-aminopeptidase (AAP), gamma-glutamyltransferase (GGT), beta-n-acetylglucosaminidase (NAG), kallikrein with creatinine as point of reference were kinetically measured in 4 urine samples (1 before c.m. administration the others as 24 hours urine samples of the following 3 days). Beside the quantitative determination of protein and albumin an electrophoresis was started, when diagnosis was obvious. Kallikrein was brought to the diagnostic palette of this study in order to include the distal segment of the nephron. The specific protein excretion patterns of nonionic c.m. in urine are not different from each other. In contradiction to this, the results of the low osmolar nonionic Iosimide compared to the high osmolar diatrizoate, show evident differences for the benefit of Iosimide.