[摘要] 目的 通过观察骨癌痛小鼠痛行为学的变化，以及磷酸化环磷酸腺苷反应元件结合蛋白(phosphorylated cAMP response element binding protein，pCREB) 和脑源性神经营养因子(brain-derived neurotrophic factor，BDNF)在脊髓背角中表达的变化，探讨pCREB和BDNF在骨癌痛产生和维持中的作用。 方法 52只雄性C3H／HeJ小鼠，采用随机数字表法，将其随机分为骨癌痛组（T组,n=26）和假手术组（S组,n=26）。T组小鼠右侧股骨骨髓腔内注射含2×105个纤维肉瘤细胞的20μL最小必须培养基（α-minimal essence medium，α-MEM），而s组注入不含肿瘤细胞的20μLα-MEM,分别于接种肿瘤细胞前1 d、接种后第4、7、10、14、21d测定自发抬足次数(spontaneous lifting times , SLTs)和机械缩足阈值(paw withdrawal mechanical threshold , PWMT)。按照分组在相应时间点处死小鼠，用免疫印迹法测定小鼠L3～5脊髓背角pCREB和BDNF的蛋白表达水平。 结果 与术前基础值和S组相比：接种后7、10、14、21d，T组小鼠自发性抬足次数[ (4.43±0.91)次,( 7.10±1.03)次,( 11.27±1.35)次,( 13.03±0.58)次]显著增加(P<0.05)；接种后10、14、21d，T组小鼠机械缩足阈值[(0.63±0.20)g,( 0.32±0.12)g,( 0.24±0.12)g]明显下降(P<0.05)，脊髓背角pCREB[(3.78±0.58),( 3.92±0.46),( 4.92±0.37)]和BDNF[(2.13±0.31),( 2.88±0.15),( 2.58±0.41)]的表达显著增加(P<0.05)。 结论 骨癌痛小鼠脊髓背角pCREB和BDNF表达增加，并且与痛行为学的改变具有相关性，提示其可能参与了骨癌痛的产生和维持。
[Abstract] Objective To investigate the role of phosphorylated cyclic-AMP response element binding protein (pCREB) and brain – derived neurotrophic factor (BDNF) in mice with bone cancer pain, via observing the change of pain behavior and the expression of pCREB and BDNF in dorsal horn of spinal cord. Methods A total of 52 male mice (C3H/HeJ) were randomly divided into tumor group(group T ,n=26)and sham group(group S ,n=26). In group T, bone cancer pain was induced by implantation 20μL of α-minimal essence medium(α—MEM)containing osteosarcoma cells into the intramedullary space of right femur．In group S, 20μL culture medium α—MEM containing no cancer cell was injected instead. Pain behavior of each group was assessed by the spontaneous lifting times(SLTs) and paw withdrawal mechanical threshold(PWMT) measured at 1 day before inoculation and at 4,7,10,14,21 days after inoculation．Another 3 mice were sacrificed at the corresponding time point and the spinal cord L3～5 were obtained for determination the expression of pCREB and BDNF by western blotting．Results Compared with preoperative base level and group S:at 7,10,14,21 days after inoculation, the obvious increasing of SLTs[ (4.43±0.91),( 7.10±1.03),( 11.27±1.35),( 13.03±0.58)]were observed in group T (P<0.05); at 10,14,21 days after inoculation, the significant decreasing of PWMT[(0.63±0.20)g,( 0.32±0.12)g,( 0.24±0.12)g] were observed in group T (P<0.05) and the expression of pCREB[(3.78±0.58),( 3.92±0.46),( 4.92±0.37)] and BDNF [(2.13±0.31),( 2.88±0.15),( 2.58±0.41)] in group T were obviously increased (P<0.05). Conclusion The expression of pCREB and BDNF in dorsal horn of spinal cord were increased in a mouse model of bone cancer pain ，corresponded with the pain behavior . Suggesting spinal cord pCREB and BDNF may be involved in the development and maintenance of bone cancer pain in mice.
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