大鼠皮肤癌痛模型的建立

Establishment of a rat model of skin cancer pain

目的:探讨足底皮下注射大鼠乳腺癌Walker256细胞建立大鼠皮肤癌痛模型的可行性。方法:SD雄性大鼠随机分为正常对照组、假接种组、模型组。模型组大鼠于后足跖面皮下接种Walker256细胞悬液200μL,假接种组则注射等量的灭活细胞,正常对照组不接种。记录大鼠荷瘤足外观,测量足体积,观察疼痛行为学;荷瘤皮肤行Masson染色,并用免疫组化染色检测脊髓星形胶质细胞和小胶质细胞活化情况;酶联免疫法检测荷瘤皮肤神经生长因子(NGF)、白细胞介素1β(IL-1β)和肿瘤坏死因子-α(TNF-α)的表达。结果:接种后第2天,模型组大鼠后足垫部出现红肿,随时间延长加重,观察结束时仍未消退,同时足体积持续增加;接种后第8～17天,模型组出现机械痛敏和热痛敏,痛阈均低于假接种组(P <0. 05),假接种组有短暂轻度红肿。模型组大鼠后足跖面皮肤内见大量肿瘤细胞浸润,脊髓背角可见活化的小胶质细胞及星型胶质细胞。模型组大鼠荷瘤皮肤内NGF、IL-1β和TNF-α表达均较假接种组增加(P <0. 05)。结论:通过足底皮下注射Walker256细胞成功建立了大鼠皮肤癌痛模型。

Aim: To investigate the feasibility of establishing a rat skin cancer pain model by injecting cultured Walker256 rat breast cancer cells into foot skin. Methods: SD male rats were randomly allocated into normal control group,sham implanting group,and model group. In the model group,200 μL Walker256 cells suspension was subcutaneously injected into one posterior foot of rats;in sham implanting group,the rats were injected with an equal volume of dead cells;the rats in normal control group were not treated. The appearance of the feet bearing tumor cells was observed,the volume of the feet was recorded as well as the pain behavior. The foot skin tissue bearing tumor cells samples were prepared and Masson staining was performed. Immunohistochemistry staining was used to detect activation of astrocytes and microglias in the spinal cord. Moreover,ELISA was performed to determine the contents of NGF,IL-1β and TNF-α in the skin tissue bearing tumor cells. Results: Red and swollen feet were observed in the model group from 2 days after tumor cell implanting,which became severe with time,and the phenomenon existed till the end of the observation. Meanwhile,foot volume kept increasing in the model group,significant mechanical allodynia and thermal hyperalgesia were observed from 8 to 17 days in the model group,and the mechanical allodynia threshold and thermal hyperalgesia threshold were lower than those of sham implanting group( P < 0. 05). Slight red and swollen skin temporally appeared on the foot of the sham implanting group. A large number of tumor cell infiltration in skin was found,and the activation of astrocytes and microglias was detected in the spinal cord dorsal horn in the model group. The contents of NGF,IL-1β and TNF-α increased in skin tissue bearing tumor cells in the model group compared with those in sham implanting group( P < 0. 05). Conclusion: A rat model of skin cancer pain has been successfully established by subcutaneously injecting Walker 256 breast cancer cells.