Pathological changes in rats with ischemic stroke induced by improved photochemical embolization

doi:10.12307/2022.036

Abstract

Abstract: BACKGROUND: A rat model of photochemical embolization can simulate ischemic stroke well, with the advantages of specific damage to the brain area, high reproducibility and low mortality. However, the choice of light source and the concentration of rose bengal injection have certain effects on the model. So, a detailed evaluation is needed to determine whether the animal model is established successfully.
OBJECTIVE: To establish a stable model of ischemic stroke in rats that is less liable to recover spontaneously, and to explore the pathological changes in the infarct region and behavior changes in rats.
METHODS: A total of 52 male Wistar rats were randomly divided into sham operation group (n=6) and photochemical embolization group (n=46). In the photochemical embolization group, 20, 40, and 80 mg/kg rose bengal was injected into the rat femoral vein to make photochemical embolization models, and meanwhile the optimal rose bengal concentration was screened out. The remaining 28 rats were subjected to photochemical embolization. Rats in the sham operation group were not irradiated with laser and were not injected with rose bengal dye. TTC staining was used to reveal the changes in infarct size at 1 day after injection with different concentrations of rose bengal. NeuN staining was used to observe neuronal death in the infarct region at 1, 3, 7, and 14 days after photochemical embolization. Iba-1, GFAP, and GLUT-1 staining were employed to observe the changes of inflammatory responses, glial scars and blood vessels in the infarct region after photochemical embolization. Cylinder experiment and grid error experiment were used to evaluate the behavioral changes of rats after photochemical embolization.
RESULTS AND CONCLUSION: Injection with 80 mg/kg rose bengal caused the largest size of stroke cavity, resulting in a high reproducibility and a low animal mortality. A stable stroke cavity could be formed within 7 days after injection. Relatively stable glial scar zone formed at 7 days after photochemical embolization, but inflammatory reactions gradually aggravated in 1-14 days. Photochemical embolization reduced the area of blood vessels near the stroke cavity, and the area tended to be stable at 14 days. The rats experienced long-term decline in sensation and motor function after photochemical embolization. To conclude, the rat model of photochemical embolization is stable and not easy to recover spontaneously, which is suitable for studying the pathological changes after ischemic stroke.

Key words: ischemic stroke, photochemical embolization, pathology, behavior, rat, animal model

CLC Number:

Li Shulun, Hao Peng, Hao Fei, Duan Hongmei, Zhao Wen, Gao Yudan, Yang Chaoyang, Li Xiaoguang. Pathological changes in rats with ischemic stroke induced by improved photochemical embolization[J]. Chinese Journal of Tissue Engineering Research, 2022, 26(2): 218-224.

Figures/Tables 7

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