Iodinated contrast media alter immune responses in pro-inflammatory states

Abstract

Background: Hypertonic saline causes a transient elevation of blood osmolality and has been shown to alter cellular inflammatory responses in pro-inflammatory states. Intravascular administration of iodine contrast media also causes a transient elevation of blood osmolarity. Purpose: To investigate the effect of iodine contrast media on leukocyte–endothelial interaction in vivo using intravital microscopy. Material and Methods: Male Sprague-Dawley rats ( n=36) were randomized into six groups and were treated with: saline, high osmolar contrast medium, low osmolar contrast medium, and endotoxin alone and in combination with the high and low osmolar contrast media. The effect on leukocyte–endothelial interaction in the post-mesenteric venules was observed using the technique of intravital microscopy. The sequence of leukocyte rolling velocity, leukocyte–endothelial cell adherence, and transmigration was recorded and analyzed at 10 min intervals to a maximum of 120 min. Results: Endotoxin significantly decreased the rolling velocity and increased the adherence and transmigration of leukocytes in a time-dependent manner. Both types of iodine contrast media attenuated this pro-inflammatory response to endotoxin. This effect began between 60 and 70 min after the onset of the experiment. Conclusion: Hyperosmolar and lower osmolar iodine contrast media attenuate the pro-inflammatory leukocyte–endothelial response to endotoxin in vivo.