Reperfusion-induced injury to the blood-brain barrier after middle cerebral artery occlusion in rats. Stroke

Background and Purpose The integrity of the blood-brain barrier may play an important pathophysiological role during postischemic reperfusion. To determine the factors that lead to exacerbation of brain injury by reperfusion, we investigated changes in cerebral blood flow, blood-brain barrier permeabil-ity, edema formation, and infarction in permanent or tempo-rary middle cerebral artery occlusion in rats and studied the relation between local cerebral blood flow and blood-brain barrier disruption. Methods Middle cerebral artery occlusion was performed with the rat suture model, allowing either permanent (6 hours) or temporary occlusion (3 hours of occlusion and 3 hours of reperfusion). We measured brain water, ion contents, and infarct volumes and determined cerebral blood flow using laser Doppler flowmetry and blood-brain barrier permeability with pH]a-aminoisobutyric acid. Results During occlusion, cerebral blood flow was reduce