Blood-brain barrier, cerebral blood flow, and brain edema in spontaneously hypertensive rats with chronic focal ischemia.

Abstract

This study was conducted to explore the participation of blood-brain barrier (BBB) permeability and cerebral blood flow (CBF) on the development of ischemic brain edema in rats with chronic arterial hypertension. Young spontaneously hypertensive rats were used, and focal ischemia was produced by occluding the distal middle cerebral artery (MCA). On day 7 after MCA occlusion, BBB permeability and CBF were measured by autoradiographic methods using 14C-alpha-amino-isobutyric acid (AIB) and 14C-iodoantipyrine. BBB permeability (transfer constant for AIB) was significantly higher in the ischemic center and periphery. The CBF of the ischemic cortex showed a graded reduction from the ischemic center to the surrounding area. The ischemic brain regions showed significantly decreased specific gravity. We conclude that SHRSP may be more vulnerable to BBB disruption after ischemia.