Objective: To establish the cerebral hyper-perfusion model after chronic forebrain ischemia in rats.
Methods: A total of 72 male rats were equally randomized into 2 modeling groups. The ligation of bilateral common carotid artery could induce chronic forebrain ischemia. And 36 rats were randomly grouped by ischemia duration: control group (n = 9), sham group (n = 9), 2-week ischemia group (n = 9) and 4-week ischemia group (n = 9). The blood flow in frontal lobe was measured at pre- and post-ligation. The neurological score and cerebral infarction area were also compared among the groups. The cerebral reperfusion was concurrently undertaken with an infusion dose of phenylephedrine at 4 µg×kg(-1)×min(-1) via tail vein to produce cerebrally hyperperfused blood flow rate over 200% of baseline following chronic ischemia. According to cerebral hyper-perfusion duration, 36 rats were randomly assigned into 4 groups: control group (n = 9), saline infusion group (n = 9), 30-minute cerebral hyper-perfusion group (n = 9) and 2-hour cerebral hyper-perfusion group (n = 9). The blood flow in frontal lobe was measured before and after cerebral hyper-perfusion. The neurological score, blood-brain barrier permeability and dry-wet weight ratio of brain also were compared among the groups.
Results: The forebrain blood flow decreased by 67% ± 2% after the ligation of bilateral common carotid artery. There was significant difference between cerebral hyper-perfusion and saline infusion groups (P < 0.01). No statistic difference was observed in neurological score and cerebral infarction area between 2-week ischemia and control groups. But it was obvious between 4-week ischemia and control groups. The permeability in blood-brain barrier of rats significantly increased in 2-hour hyper-perfusion group (P < 0.05).
Conclusion: The 2-hour duration of cerebral hyper-perfusion following a 2-week ligation of bilateral common carotid artery may establish a reliable cerebral hyper-perfusion model in rats.