Effect of contrast media on red cell filtrability and morphology

The effects of radiological contrast media on red cell morphology and rigidity have been studied. It has been shown that all the contrast agents studied, even when iso-osmolar with plasma, produce changes in red cell morphology, revealing the intrinsic chemotoxicity of contrast medium molecules. The changes are greatest with the most strongly protein-bound medium investigated--meglumine ioglycamide. The effects on red cell rigidity, on the other hand, appear purely a function of osmolality, being entirely reproducible with hyperosmolar solutions of saline. At concentrations iso-osmolar with plasma no effect on deformability is observed. Since the increased rigidity of red cells induced by contrast medium adversely affects blood flow, the use of the new low-osmolality contrast media is particularly recommended in pulmonary angiography and renal arteriography.