脊髓小胶质细胞在SD大鼠骨癌痛中的变化

目的 观察SD大鼠一侧胫骨注射同系Walker 256癌细胞后脊髓小胶质细胞的变化.方法 腹水传代Walker 256癌细胞种植于大鼠一侧胫骨建立骨癌痛模型,25只雌性SD大鼠,体质量150～180 g,随机均分为5组:对照组(N)、热杀死肿瘤细胞组(K)、骨癌痛早期组(C1,种植后第6天)、骨癌痛中期组(C2,种植后第12天)、骨癌痛晚期组(C3,种植后第18天).结果 骨癌痛大鼠在出现自发痛行为与机械性痛觉过敏的同时,两侧脊髓L4～L6 OX-42免疫组织化学染色显著增强,细胞明显增大,染色加深,与N组及K组比较,差异均有统计学意义(P<0.05,P<0.01);OX-42染色增强以C1组最为显著,术后第6～18天逐步降低,C1组与C2或C3组比较,差异均有统计学意义(P<0.05,P<0.01).结论 胫骨注射Walker 256癌细胞后激活脊髓小胶质细胞;小胶质细胞在两侧脊髓灰质后角均有激活,反映了本模型骨癌痛特征中"镜像痛"的产生机制;小胶质细胞在骨癌痛早期激活最为明显.

Variation of spinal microglia in a SD rat model of bone cancer pain

Objective To explore the spinal microglial alteration in a rat model of bone cancer pain produced by injecting syngeneic Walker 256 rat mammary gland cancer cells into the unilateral tibia of female SD rats. Methods Bone cancer pain model was created by receiving left superior extremity intra-tibial inoculations of Walker 256 syngeneic SD rat carcinoma cells which were cultured and proliferated in vivo to produce ascites in 25 female SD rats weighing 150-180 g. The rats were divided by 5 groups randomly:significantly enhanced and activated in the L4-L6 superficial spinal cord bilateralis in rats with inoculatin of Walker cancer cells, characterized by enhanced immunostaining of OX-42 (microglial marker,P< 0.05,P <0.01). Spinal OX-42 staining progression was decreased on the day 6 to day 18 post cell inoculation,and it was distinguished on the day 6 post inoculation (P <0.05 ,P <0.01). Conclusion The injection of Walker 256 cancer cells into the tibia activates the spinal microglia. Furthermore, the microglia activated in ipsi-and contralateral superficial dorsal horns highlights the possible involvement in the mirror imaging pain phenomenon in neuroethology of this model of bone cancer pain. Microglia may play important role in the emerge of bone cancer pain in the earlier phase.