The antioxidant tirilazad does not affect cerebral blood flow or histopathologic changes following severe ischemia in rats

We studied the effect of tirilazad, an aminosteroid with radical scavenging effect, or its vehicle on cerebral blood flow and neuronal death when given before 15 min of severe global ischemia achieved by hypotensive bilateral carotid clamping in rats. Ischemic blood flows less than 1% of the non-ischemic values were seen in the forebrain regions. Hypoperfusion occurred in all regions 60 min after the insult with flow values 21–58% of those in the non-ischemic group. Tirilazad had no effect on cerebral blood flow in the non-ischemic rats, nor in those decapitated during or after the insult. Five days postischemia neuronal damage had developed in all regions examined, but no significant differences were seen between the tirilazad-and the vehicle-treated rats.