Morphologic degeneration of human microvascular endothelial cells induced by iodinated contrast media

Rationale and Objectives. The purpose of this study was to characterize the adverse effects of iohexol and ioxaglate on human microvascular endothelial cells, which may result in phlebitis, pain, and thrombosis. Materials and Methods. The degree of morphologic degeneration and of lactate dehydrogenase (LDH) efflux into the extracellular medium (as an index of cell viability) were determined in endothelial cell culture exposed for 10, 30, or 60 minutes to ioxaglate or iohexol (ionic and nonionic contrast media, respectively) at iodine concentrations of 100 or 150 mg/mL. Results. Ioxaglate induced concentration- and time-dependent morphologic degeneration, including shrinkage and loss of the cell tip in 20%-80% of endothelial cells; iohexol did not. After 60 minutes of exposure, ioxaglate at the higher concentration (150 mg iodine per milliliter) significantly increased the LDH signal (ie, the percentage of LDH released), to 20%. Conclusion. The present findings demonstrate that ioxaglate but not iohexol causes morphologic degeneration of the microvascular endothelial cells. This direct cytotoxic action of ioxaglate probably causes endothelial cell dysfunction, closely associated with the occurrence of phlebitis, pain, and thrombosis.