Granulocyte chemotaxis. Chemoattractive properties of a synthetic tripeptide are inhibited by radiographic contrast media.

The under agarose method for evaluation of leucocyte chemotaxis was used to investigate the effect of radiographic contrast media (CM) on granulocyte locomotion. The CM tested had no chemoattractive properties. CM inhibited N-fmlp, a synthetic formylated Met-tripeptide, which is a strong chemotactic agent and an analogue to chemotatic peptides produced by bacteria. The inhibition of N-fmlp was most pronounced for diatrizoate. Equiosmolal saline was not so inhibitive. Therefore, some part of the inhibition was caused by factor(s) other than hyperosmolality inherent in the CM solution.