Alteration of human blood cells and changes in plasma mediators produced by radiographic contrast media

In vitro incubation of human blood cells with iodinated radiographic contrast media (RCM) produced marked effects which were dose-dependent: erythrocytes showed crenation which was reversible; neutrophil leukocytes released the lysosomal enzyme β-glucuronidase; basophil leukocytes released histamine; and platelets released serotonin as well as β-glucuronidase. The release reaction could not be attributed to cell lysis, as demonstrated by the release of the cytoplasmic enzyme lactic dehydrogenase (LDH). In normal human serum, RCM produced activation of the complement system with lysis of cells. This RCM-induced complement activation seemed to occur via the alternate pathway. Stabilizers and cations present in the clinically used RCM solutions did not produce any complement changes.