Abstract: ObjectiveTo compare the difference between the two methods in building the hypoxic-ischemic encephalopathy model, and to investigate the effect of anaesthesia and the hypoxic-ischemic intermission on the HIE model.Methods7-day-postnatal SD rats were used to build the HIE models. In the traditional group, rats were exposed to 8% O2 for 2h 2～3 h after left carotid artery ligation followed aether anaesthesia. However, rats in the improved group received hypoxia immediately after operation without previous anaesthesia. The quantity of the dead rats in two groups was counted. The morphologic changes in the brain 3 days after the hypoxic-ischemic insult were observed, and the grades of the total brain pathological evaluations of two groups were compared.ResultsNone of the animals died in the improved group, but 6 died in the traditional group. Remarkable degeneration or necrosis was detected in the ipsilateral cerebral cortex and hippocampus in the improved group, but not detected in most of the rats in the traditional group. The total grade of brain pathological evaluation in the traditional group was 130, significantly lower than that in the improved group, which was 550(P<0.01).ConclusionThe improved approach show the advantage of low mortality and credible pathological change to build the HIE model compare with the traditional methods.

Key words: hypoxic-ischemic encephalopathy, animal model, modeling, rat