Contrast agents and enzyme inhibition. II. Mechanisms.

The inhibition of enzymes by radiological contrast agents has been invoked to explain some of their clinical effects. In a previous paper, in-vitro studies of the inhibition of the enzyme acetylcholinesterase were presented and some clinical correlations were discussed. More detailed studies, described here, have now shed new light on the mechanisms involved in this important phenomenon. Because the findings restore the iodine atoms to a central role, they have important general implications for contrast agent pharmacology.