Effect of ionic and non-ionic contrast media on morphology of human erythrocytes

The effects of solutions of the ionic contrast media diatrizoate, iocarmate and metrizoate and the non-ionic metrizamide on red cell morphology were compared by interference contrast optics in vitro. All the media produced changes, in solutions both isotonic and hypertonic to blood. The changes increased with increasing volume ratio (contrast medium/blood). At low volume ratio the cells were transformed into crenated cells (echinocytes) in ionic solutions both hypertonic and isotonic to blood. At high volume ratio the hypertonic ionic media caused the red cells to become shrunken (desiccocytes), corresponding to the shrinkage caused by hypertonic saline. The low osmotic non-ionic metrizamide never produced desiccocytes but echinocytes also in high volume ratio. In solutions isotonic with blood metrizoate and metrizamide transformed more cells into echinocytes than the diatrizoate and iocarmate solutions.