Blood-brain barrier lesions in acute hypertension in rabbits after unilateral X-ray exposure of brain.

Acute hypertension was induced by metaraminol at different time intervals following irradiation in rabbits exposed to unilateral X-ray irradiation against the brain (3000 R) and in control animals. Hypertension resulted in a few areas of Evans blue extravasation in control animals. In the irradiated animals there was a marked increase in tracer extravasation on the half of the brain exposed to X-rays, indicating an increased vulnerability of cerebral vessels to blood pressure increase after irradiation.