The effect of non-ionic X-ray contrast media on glial cells in vitro

By Aardal, N.P. - Andersen, K.J. - Christensen, E.I. - Vik, H.

The rat glial cell line C6 has been used to assess the toxicity of two different iodine-based X-ray contrast media: the non-ionic dimer iodixanol and the non-ionic monomer iohexol. The cells were exposed to increasing concentrations (0-75mg iodine/ml) during exponential growth (up to eight days). A dose-dependent inhibition of cell growth was observed when iohexol was added to the culture medium, but not when iodixanol was added. While iohexol had a profound, long lasting effect on cell viability, iodixanol, after an initial adverse impact, had no effect. Iohexol and iodixanol both caused increased lysosomal peptidase activity, as shown for dipeptidyl peptidase, but had no effect on other lysosomal enzymes, such as acid beta-galactosidase. Electron microscopy revealed no changes in the cellular ultrastructure after exposure to iodixanol. In contrast, there was extensive vacuolisation in the cells exposed to iohexol, including a significantly increased number of autophagocytic vacuoles. It would appear that iodixanol has only minor effects on glial cells in culture, compared to those induced by iohexol.