Regional cerebral blood flow in rats with cerebral ischemia produced by bilateral vertebral and carotid artery occlusion.

Abstract

Regional cerebral blood flow (rCBF) was measured prior to, during and after global cerebral ischemia in rats. Global cerebral ischemia was produced by 10 or 30-min occlusion of both common carotid arteries which was done 24 h after the permanent electrocauterization of bilateral vertebral arteries. The rCBF was measured using the radioactive microsphere technique. In rats subjected to 10-min cerebral ischemia, rCBF in 9 brain regions was reduced to 11.3-54.8% (mean: 26.9%) of that of the sham operated control. Ten minutes after recirculation, hyperperfusion was observed in the cerebral cortex, hippocampus and striatum. A moderate recovery was detected in the accumbens nucleus + olfactory tuberculum, thalamus and hypothalamus. However, rCBF in these 6 regions was again decreased 20-30 min later, and it recovered to levels > 50% of the control 60 min after the ischemic event. In the other 3 regions (cerebellum, superior and inferior colliculus, pons + medulla), rCBF increased toward the control level gradually, and it completely recovered 60 min after recirculation. In rats subjected to 30 min cerebral ischemia, rCBF in 9 brain regions was reduced to 1.77-26.3% (mean: 9.6%) of that of the control. The post-ischemic hyperperfusion in the cerebral cortex and hippocampus and a moderate recovery of rCBF in the striatum and accumbens nucleus + olfactory tuberculum were observed 10 min after the cerebral ischemia. rCBF in these 4 regions remained under the control levels from 20-60 min after recirculation. The change of rCBF in the other regions was similar to that in the 10-min ischemic group, but the recovery was less at 60 min after recirculation. The abnormalities in the post-ischemic rCBF may be involved in the behavioral, EEG and neurochemical changes observed after the cerebral ischemia.