Muscle toxicity of diatrizoate and iohexol in rabbits. A model for local tissue damage.

The potential tissue irritating effect of diatrizoate and iohexol was studied by injecting the contrast media into the right longissimus dorsi muscle of rabbits. The left muscle served as control. The animals were sacrificed 3 days after the injection, at which time muscle tissue was examined for macroscopic changes and loss of the muscle enzyme creatine kinase (CK) from the injection site was determined. An irregular area of necrotic muscle tissue and a hemorrhage was found at the injection site in rabbits given diatrizoate, whereas iohexol only caused hemorrhage. The local loss of CK activity following diatrizoate (0.64 g muscle tissue) was statistically significantly greater than following iohexol (0.18 g muscle tissue). It is concluded that this model seems to be useful for identification of the irritating potential of contrast media. It is also concluded that diatrizoate caused more damage to the local muscle tissue than iohexol.