【摘要】 目的观察骨癌痛模型大鼠患侧腰段脊髓 p38α和 p38p 的分布及细胞定位,探讨其在骨癌痛中的作用机制。方法选择雌性 SD 大鼠20只,随机分为2组,每组10只:A 组(对照组):左侧胫骨上段骨髓腔注入3μl Hanks 液;B 组(模型组):左侧胫骨上段骨髓腔注入3μl MADB-106大鼠乳腺癌细胞(4.8×10~3/μl)。术前及术后14 d,各组大鼠隔日观察机械痛及辐射热痛阈值变化。第14 d,取大鼠脊髓14～6节段,采用免疫组织化学 ABC 法和荧光双标法观察骨癌痛模型大鼠患侧腰段脊髓 p38α和 p38β免疫反应阳性产物的分布变化和细胞定位。结果 A 组大鼠对机械、辐射热痛刺激的缩爪阈值在术后各时间点组内相比,差异无统计学意义;B 组大鼠对辐射热痛刺激缩爪阈值在术后的前6 d 与 A 组相比,差异有统计学意义(P<0.05);术后第14 d,与 A 组大鼠对机械痛刺激缩爪阈值和辐射热痛阈值相比,B 组差异有统计学意义(P<0.05)。B 组大鼠患侧腰段脊髓背角Ⅰ～Ⅳp38α和 p38β免疫反应吸光值明显高于 A 组,两组相比差异有统计学意义(均 P<0.05)。荧光双标显示患侧腰段脊髓背角 p38α与神经元特异性核蛋白标志物 NeuN 有共表达,p38β与小胶质细胞标志物 OX-42有共表达。结论脊髓 p38α和 p38β参与了骨癌痛的发生和发展,p38α主要在脊髓神经元表达,而 p38β则在脊髓小胶质细胞中表达。更多还原

【Abstract】 Objective To examine the cellular distribution and location of p38α/βisoforms in the lumbar spinal cord of the bone cancer pain rats.Methods Twenty SD female rats weighing 180-220 g were randomly divided into 2 groups （n=10 each）:group A （control group）:intra-tibial injection of 3 μl Hank’s solution;group B （model group）:intra-tibial injection of 3 μl MADB-106 mammary gland carcinoma cells of rats （4.8 x 10³/μl）.Mechanical withdrawal threshold and radiant heat threshold of rats’ hind paws were measured every other day from one day before operation until 14 days later.The lumbar 4～5 spinal cord was removed on the 14^th day.The cellular distribution and location of the spinal p38α/β immunoreactivity were detected by immunohistochemistry SABC and double immunofluorescence methods.Results No significant differences in mechanical withdrawal threshold and radiant heat threshold were found at all time points in group A.During the first 6 days of post-operation there was obvious difference in radiant heat stimulus between group A and B （P<0.05）;on the 14^th day after operation,mechanical pain threshold and radiant heat threshold in group B were significantly different from that of group A（P<0.05 ）.The p38α/β immunoreactivity of group B in laminae Ⅰ～ Ⅳ of dorsal horn showed stronger staining than group A（P< 0.05）.Double immunofluorescence confocal micrographs showed that spinal p38α and the neuronal marker neuronal N （NeuN） were colocalized in the dorsal horn,indicating that p38α was expressed in neurons. Double immunofluorescence micrographs demonstrated that antibodies againsted p3819 and the microglia marker OX42 labeled the same cell,indicating that p38β was expressed in microglia.Conclusion Our studies indicate that p38α and p38β are invovled in the generation and maintenance of bone cancer pain states,p38α is predominantly expressed in neurons,while p38β is expressed in microglia.更多还原