Effects of Intra-arterially Injected Contrast Media on Microvessels in the Ratʼs Cecal Mesentery

The effect of contrast media on the permeability of microvessels in the ratʼs cecal mesentery was examined in vivo. Contrast media were injected intraarterially and flowed through the vessels under observation for 30 seconds. Subsequent disposition of injected colloidal carbon particles was used as a marker for permeability changes. Microscopic observations and photographic records were made of the vessels exposed to the radiopaque materials. There was no significant increase in the permeability of normal microvessels after exposure to contrast materials. An increase in permeability due to exposure to contrast media was noted in two cases1) in vessels damaged during preparation for observation before exposure to contrast media, and 2) in vessels which became occluded after exposure to contrast media. The purpose of this study was to evaluate the permeability effects of intra-arterial injection of contrast materials following relatively short exposure of microvessels to these hyperosmolar solutions.