Comparative study of the adverse effects of various radiographic contrast media, including ioversol, a new low-osmolarity medium. I. Histamine release.

Histamine release induced by some radiographic contrast media (RCM) such as iohexol, iopamidol and meglumine sodium amidotrizoate (MSA) was studied in comparison with ioversol, a new low-osmolarity contrast medium. Although all of the RCM caused a dose-related histamine release from rat peritoneal mast cells, that induced by ioversol was the least. MSA induced more remarkable histamine release than did sodium chloride at each of the corresponding osmolarities, except under hypoosmolar conditions. Moreover, in guinea pig lung perfusion, RCM, especially ioversol, iohexal and iopamidol, induced only a weak histamine release in both non-sensitized and sensitized animals. However, when MSA was perfused in sensitized animals, a large amount of histamine was detected in the lung effluents. These results suggest that nonionic RCM, including ioversol, can be used more safely than MSA for diagnostic examination.