大麻素受体2在胫骨癌痛大鼠脊髓背角细胞中的表达

目的:观察胫骨癌痛大鼠脊髓大麻素受体2(CB2)表达的变化,探讨CB2在骨癌痛中作用及其可能的脊髓机制。方法:雌性SD大鼠56只,体重160-180g,随机分为7组(n=8):对照组、假手术组、骨癌痛组,假手术组和骨癌痛组又各分为3个亚组(术后7d、14d和21d组),分别用免疫印迹法检测各组大鼠脊髓水平CB2表达的变化,激光共聚焦技术观察CB2的表达部位。结果:免疫印迹结果显示对照组基本没有CB2的表达,与对照组相比,假手术组及骨癌痛组脊髓CB2表达水平升高(P<0.05);与假手术组相比,骨癌痛7d组脊髓CB2蛋白表达明显上调(P<0.05)。激光共聚焦技术显示CB2主要表达于脊髓小胶质细胞和星形胶质细胞。结论:胫骨癌痛大鼠脊髓背角有CB2表达,早期为其表达的高峰,且主要表达于小胶质细胞和星形胶质细胞。

The expression of cannabinoid receptor 2 in cells from spinal dorsal horn of rats with tibial bone cancer pain

Objective:To investigate expression changes of spinal cannabinoid CB2 receptor and the role in pain facilitation and spinal mechanisms in the rat model of bone cancer pain.Methods: Syngeneic Walker 256 mammary gland carcinoma cells were injected into the tibia medullary cavity to establish the rat model of bone cancer pain.Fifty-six female Sprague-Dawley rats weighing 160-180g were randomly divided into following groups(n=8):(Ⅰ)Nave group;(Ⅱ)sham group(7days after surgery);(Ⅲ)bone cancer pain group(7days after surgery);(Ⅳ)sham group(14 days after surgery);(Ⅴ)bone cancer pain group(14 days after surgery);(Ⅵ)sham group(21 days after surgery);(Ⅶ)bone cancer pain group(21 days after surgery).To test the CB2 expression in the spinal cord by western blot analysis,observe CB2 position in the spinal cord by confocal.Results: Western blot analysis showed that nave group hardly expressed CB2.Compared with nave group,CB2 expression in the spinal cord was significantly increased at sham group and bone cancer pain group(P<0.05),but compared with sham group,CB2 expression was significantly increased at 7th after surgery(P<0.05).Immunofluorescence results revealed CB2 mainly expressed in microglia and astrocytes.Conclusion: CB2 was expressed in rat tibial bone cancer pain model,and the peak of expression was in the early days,in addition,CB2 almost expressed in microglias and astrocytes.