TOXICITY OF THE RADIOGRAPHIC CONTRAST MEDIA IOPAMIDOL, IOHEXOL AND METRIZAMIDE TO CELL CULTURES

Cultured murine embryonal carcinoma cells were exposed to the tri‐iodinated radiographic contrast media iopamidol, iohexol and metrizamide at concentrations below those used for clinical myelography and examined by light and electron microscopy. Cytologic changes consisting of swelling and vacuolation of mitochondria and other cytoplasmic organelles were observed within 1 h of exposure to the contrast media. By 12 h of incubation cells altered shape, lifted from the culture dish and eventually died. These changes occurred irrespective of the osmolarity of the incubation medium and did not occur when cells were incubated in the presence of 1.16 mM EDTA or 10 mM Tris, which are present in commercial preparations of iopamidol and iohexol. Similar cytological changes were observed in cultures of neurons derived from embryonal carcinoma cells and in cultures of rat dorsal root ganglion cells. The results indicate that iopamidol, iohexol and metrizamide are cytotoxic to cells in culture at less than 20% of the concentration used for myelography and this could contribute to the adverse reactions to myelography seen in people and animals.