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 assess the time course of cellular repair after endothelial cell exposure to ionic and non-ionic contrast media. Material and Methods. Local changes at the cellular level following intraaortic 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 mg/ml, were investigated using rat endothelium as an in vivo model. A sorbitol solution iso-osmolar to iomeprol served as control. Quantitative analysis of endothelial changes by autoradiography of 3H-ththymidine-labeled endothelial cells was assessed after 3, 5 and 10 days, determining the 3H-thymidine index and the DNA synthesis rate. Results. Ioxithalamate showed a clear harmful effect on the endothelium, with an elevated 3H-thymidine index of 7.68% on day 3 and 6.89% on day 5, versus 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 endothelial cell injury. No such side effect was detectable for non-ionic contrast agents.