[An animal experimental model for evaluating endothelial damage caused by various angiographic contrast media (author's transl)].

The endothelial damage caused by X-ray contrast media is tested on "en face preparations" of the rat aorta after silver staining. Hypertonic contrast media cause dehydration of the vessels so that solutions of silver nitrate penetrate into the media during the phase of rehydration whereby medial transverse lines are stained. These artifacts can be avoided by 3 minutes rehydration of the vessels by Ringer solution prior to silver staining. In addition it is recommended to add highly diluted silver nitrate to the fixing media in order to intensify the pattern of the endothelial silver lines. Modern contrast media may cause very little endothelial damage, however, significant differences can be detected when in addition to the evaluation of larger foci damages of single endothelial cells ("brown cells" with sparing of the nuclei and "pseudonuclei") are evaluated as well. No significant differences were found between the endothelial toxicity of meglumin diatrizoate and meglumin iothalamate.