The X-ray contrast medium iodixanol detects increased colonic permeability equally well as 51Cr-labelled ETDA acid in experimental colitis of rats

Non-ionic water-soluble radiographic contrast media have been suggested as intestinal permeability probes. The authors studied the permeability of the isosmolar contrast medium iodixanol and 51Cr-labeled EDTA from the non-perforated colon after induction of colonic inflammation. Colonic inflammation and ulcerations were induced by luminal colonic instillation of trinitrobenzenesulfonic acid, dissolved in 40% ethanol. Controls received saline. 14 days later iodixanol, 320 mgI/ml, and 51Cr-EDTA were given as an enema. Urine was collected for the subsequent 6 h and subjected to high-performance liquid chromatography and gamma activity counting. Urinary recovery of iodixanol and 51Cr-EDTA increased gradually with severity of the colonic inflammation. The correlation between iodixanol and 51Cr-EDTA recovery was strong. Iodixanol shows as good properties as 51Cr-EDTA when used as intestinal permeability probe in the inflamed and ulcerated rat colon. Use of the radiopaque properties of iodixanol enable intestinal probe exposure registration by film or fluoroscopy. 34 refs., 4 figs., 3 tabs