Phagocytic properties of granulocytes after intravenous injection of ioxaglate or iohexol

To evaluate the influence of radiographic contrast media (CM) on human granulocytes, the ability of these cells to ingest latex particles after intravenous injection of ioxaglate and iohexol was investigated. Both CM inhibited the phagocytic properties of granulocytes; the inhibition was the most pronounced immediately after the injection, but inhibition was also observed 60 min after injection of ioxaglate. The inhibition 1 and 5 min after injection of CM was more pronounced after injection of ioxaglate than after injection of iohexol. However, this difference between the 2 CM was not significant. Significant inhibition of phagocytosis was found for mannitol solutions with osmolalities higher than 369 mOsm/l. Significant inhibition of phagocytosis was observed when granulocytes were isolated with either Hypaque/Ficoll or Percoll gradient centrifugation and then incubated with diatrizoate. Thus the ability of granulocytes to phagocytize latex particles was inhibited after i.v. injection of 50 ml ioxaglate or iohexol. Part of this inhibition may be due to hyperosmolality.