OBJECTIVE: To simulate the process of neonatal hypoxic-ischemic brain injury in a high altitude environment in a simulated chamber of high altitude low pressure environment, to prepare high altitude brain injury rat models at different altitudes.
Methods: 32 10-day-old SD rats were randomly divided into 4 groups, namely group A (control group) and 3 experimental groups: group B (group 2000 m), group C (group 4000 m), group D (6000 m group). The rats in the control group were bred in a barrier environment, and the rats in the experimental group were placed in a high-altitude low-pressure environment simulated cabin combined with exercise to create a neonatal high-altitude cerebral hypoxia-ischemia model. The exercise method was 60 min/d in a swimming tank in the cabin. Swimming, and living time in the simulation warehouse of plateau low pressure environment shall not be less than 20 hours per day. Rats in each group were scored on the 3rd, 7th, 11th, 15th day using Zea Longa 5-point system for behavioral scoring and venous blood was collected on the 15th day, and the red blood cell morphology was observed under a scanning electron microscope. After each group was sacrificed, brain tissues were taken for HE staining and TTC staining.
Results: (1) Neurological score: Compared with the control group rats, the behavioral scores of the experimental group B, C, and D groups were significantly different (P<0.05), and the difference between group D and the control group was very different. Significant (P<0.01). (2) HE staining results showed that: compared with the control group, the experimental group had inflammatory cell infiltration, and the degree of inflammatory cell infiltration was positively correlated with altitude. (3) TTC staining shows that cerebral cortex ischemia is obvious in rats at high altitude. (4) Observation of the red blood cell morphology under the electron microscope showed that the experimental group B had a cap-shaped structure; the C group had an irregular shape; the D group had a jagged shape.
Conclusion: In this study, a hypoxic-ischemic encephalopathy (HIE) model of neonates was made by using a high-altitude low-pressure environment simulation chamber combined with exercise to simulate a high-altitude environment. This model is stable and reliable, and is more in line with the pathogenesis of ischemic-hypoxic brain injury than other methods It is close to the clinic and can be used for related research.