Ionic and non-ionic contrast agent-mediated endothelial injury - Quantitative analysis of cell proliferation during endothelial repair

Purpose. To quantitatively evaluate endothelial injury in vivo and to asses s the time course of cellular repair after endothelial cell exposure to ion ic and non-ionic contrast media. Material and Methods. Local changes at the cellular level following intraao rtic injection of 1 mi of the ionic contrast agent ioxithalamate or 1 mi of the nonionic contrast agent iomeprol, each with an iodine content of 300 m g/ml, were investigated using rat endothelium as an in vivo model. A sorbit ol solution iso-osmolar to iomeprol served as control. Quantitative analysi s of endothelial changes by autoradiography of 3H-ththymidine-labeled endot helial cells was assessed after 3, 5 and 10 days, determining the 3H-thymid ine index and the DNA synthesis rate. Results. Ioxithalamate showed a clear harmful effect on the endothelium, wi th an elevated 3H-thymidine index of 7.68% on day 3 and 6.89% on day 5, ver sus 2.97% on day 3 and 2.55% on day 5 for iomeprol and 2.29% on day 3 and 1 .91% on day 5 for the control. Conclusion: Ionic contrast agents lead to reversible transient focal endoth elial cell injury. No such side effect was detectable for non-ionic contras t agents.