动物造模,认知功能损伤 z-bio 2022-08-29 280

　　OBJECTIVE: To irradiate the head of rats with different doses, select the appropriate dose to establish an animal model of cognitive impairment induced by ionizing radiation, and provide a research basis for studying the mechanism of ionizing radiation-induced cognitive impairment and the development of radioprotectants.

　　Methods: Twenty SPF male rats were randomly divided into control group (C group), 10Gy irradiation group (10GyIR group), 20Gy irradiation group (20GyIR group) and 30Gy irradiation group (30GyIR group), with 5 rats in each group, Group C was left untreated, and the other three groups were irradiated with 10Gy, 20Gy and 30Gy electron beams on the head of SD rats of different groups respectively. Animal mortality was calculated 30 days after irradiation, and the spatial memory ability of rats was evaluated by Morris water maze. The chemical colorimetric method was used to detect reduced glutathione and malondialdehyde in rat cerebral cortex homogenate, the content of 8-hydroxydeoxyguanosine was detected by enzyme-linked immunosorbent assay, and the HE-stained brain pathological sections were detected and observed. .

　　RESULTS: The animals in the 30GyIR group had irregular back hair, salivation and other symptoms, and severe hair loss on the head and neck. At 30 days after irradiation, no animals died in the C group. The mortality rate of the animals in the 10GyIR group and the 20GyIR group was 20%, and that in the 30GyIR group The animal mortality rate was 40%. The results of the Morris water maze positioning navigation experiment showed that the latency time of the 30GyIR group was higher than that of the other three groups during the training period of 1-5 days, and the difference was statistically significant (P<0.05). The spatial search experiment showed that the 30GyIR group Compared with the other groups, the stay time in the original platform quadrant in the 10GyIR group, the 20GyIR group, and the 30GyIR group was significantly shorter than that in the C group (P<0.05); the number of crossing the platform was significantly reduced (P<0.05). <0.05); the detection results of oxidative stress-related indicators showed that there were significant differences in GSH, 8-OHdG, and MDA concentrations between the 30GyIR group and the C group (P<0.05), and the 20GyIR group and the C group had a statistically significant difference in the MDA concentration. Significant (P<0.05); HE staining showed that the tissue structure damage in the 20GyIR group and the 30GyIR group was more serious than that in the 10GyIR group, and there were significant pathological changes such as apoptosis and necrosis of tissue cells.

　　Conclusion: The results of this experiment suggest that a single 30Gy irradiation to the head can successfully establish an animal model of cognitive dysfunction in rats.