Human blood cells ultrastructural changes and mediator release after exposure to roentgenographic contrast media.

Adverse reactions to roentgenographic contrast media (RCM) are associated with the release of mediators including complement components (anaphylatoxins), histamine and serotonin. In an in vitro study of platelets and leukocytes from 20 healthy individuals, RCM-induced release of granules from basophils and platelets was correlated with the release of histamine and serotonin respectively. The release of histamine from basophils was augmented in the presence of exogenous complement; in contrast, the release of serotonin from platelets was not dependent on the addition of exogenous complement. Although individual differences were noted, iothalamate most effectively released serotonin, whereas diatrizoate most effectively released histamine.