[Enzymuria following administration of contrast media in hypertensive rats].

Renal complications may occur in risk patients with pre-existing kidney damage if x-ray contrast media are administered. Nothing is known of the exact mechanisms of these reactions. We examined in rats with long-term renovascular hypertension and resulting nephrosclerosis the low osmolar contrast media ioxaglate, iohexol and iopamidol in respect of their renal tolerance compared with an osmotically equivalent mannite solution. Under the conditions of intravenous pyelography, we observed directly after the administration of all substances (3.5 mg/kg body weight) an enhanced enzymuria of gamma-glutamyl transpeptidase and N-acetyl-beta-D-glucosaminidase. The loss of enzyme is mainly due to the osmotic effect of the preparations. The nonionic contrast media iohexol and iopamidol produce a slighter enzymuria than the ionic ioxaglate.