EFFECT OF INTRACAROTID NONIONIC CONTRAST-MEDIA ON THE BLOOD-BRAIN-BARRIER IN ACUTE HYPERTENSION

PURPOSE: To determine whether acute hypertension (HT) is a risk factor for damage to the blood-brain barrier in carotid angiography with non ionic contrast media. METHODS: Anesthetized rats received intravenous injections of technetium-99m-pertechnetate and horseradish peroxidase. Two groups of rats received metaraminol to raise their blood pressure to between 165 and 190 mmHg peak systolic and then received intracaro tid injections of saline or iopamidol. Two other groups remained normo tensive and received intracarotid injections of saline or iopamidol. A nimals were perfused with a fixative solution and their brains removed . Activity of extravasated Tc-99m-pertechnetate was determined to asse ss blood-brain barrier breakdown. Brains were then sectioned, treated histochemically to visualize extravasated horseradish peroxidase, and ranked visually according to horseradish peroxidase staining. RESULTS: Extravasation of both tracers was significantly greater in the hypert ensive group that received contrast media than in the other three grou ps. CONCLUSIONS: Acute hypertension potentiates the blood-brain barrie r-damaging effects of nonionic contrast media during carotid angiograp hy in rats.