BLOOD-BRAIN-BARRIER, CEREBRAL BLOOD-FLOW, AND BRAIN EDEMA IN SPONTANEOUSLY HYPERTENSIVE RATS WITH CHRONIC FOCAL ISCHEMIA

This study was conducted to explore the participation of blood-brain b arrier (BBB) permeability and cerebral blood flow (CBF) on the develop ment of ischemic brain edema in rats with chronic arterial hypertensio n. 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 C-14-alpha-amino-isobutyric acid (AIB) and C-14-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 ce nter to the surrounding area. The ischemic brain regions showed signif icantly decreased specific gravity. We conclude that SHRSP may be more vulnerable to BBB disruption after ischemia.