Cerebrovascular effects of intraarterial CO/sub 2/ in quantities required for diagnostic imaging. [Rats]

The recent development of digital subtraction angiography (DSA) has renewed interest in the use of gasses, especially carbon dioxide, as contrast agents. Both early physiologic studies and recent clinical reports suggest that arterial CO/sub 2/-DSA is a safe and useful diagnostic tool in the examination of extremity circulation. The present study examined the neurologic sequelae, pathologic changes, and effects on the blood-brain barrier to intravenous Evans-Blue and horseradish peroxidase of intracarotid CO/sub 2/, in albino rats. As with other forms of cerebral gas embolization, CO/sub 2/produced multifocal ischemic infarctions and disrupted the blood-brain barrier to macromolecular tracers. The site of the barrier lesion is the endothelial cell membrane, although the precise mechanisms of damage remain unknown.