中文摘要：

目的 通过观察骨癌痛小鼠痛行为学的变化,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,采用随机数字表法分为骨癌痛组（T组）和假手术组（S组）,每组26例.T组小鼠右侧股骨骨髓腔内注射含2×10^5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20μ1α-MEM,分别于接种肿瘤细胞前1d、接种后第4、7、10、14、21天测定自发抬足次数（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组比较：接种后7、10、14、21d,T组小鼠SLTs[（4.43±0.91）,（7.10±1.03）,（11.27±1.35）,（13.03±0.58）次]显著增加（P＜0.05）;接种后10、14、21 d,T组小鼠PWMT[（0.63±0.20）、（0.32±0.12）、（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.

英文摘要：

Objective To investigate the role of phosphorylated cyclic-AMP response element binding protein （pCREB） and brain-derived neurotrophic factor （BDNF） in 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 20 μl of α-minimal essence medium （α-MEM） containing osteosarcoma cells into the intramedullary space of right femur.In group S,20 μl culture medium α-MEM containing no cancer cells was injected instead.Pain behavior of animals in both groups was assessed by the spontaneous lifting times （SLTs） and paw withdrawal mechanical threshold （PWMT） measured at 1 day before and at 4,7,10,14 d,and 21 d after inoculation.Another 3 mice were sacrificed at the corresponding time point and the L3-5 spinal cords were obtained for determining the expressions of pCREB and BDNF by western blotting.Results Compared with preoperative base level,the levels of SLTs in group S were significantly increased at 7,10,14,21 d after inoculation,the obvious increasing of SLTs [（4.43±0.91）,（7.10±1.03）,（11.27 ±1.35）,（13.03 ±0.58）,respectively] （P＜0.05）,at 10,14,21 d after inoculation,the significant decreasing of PWMT[（0.63±0.20）,（0.32±0.12）,（0.24±0.12） g] were observed in group T （P＜0.05） and the expressions 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）.Conclusions The expressions of pCREB and BDNF in dorsal horns of spinal cords were increased in a mouse model of bone cancer pain,accompanied by the pain behavior,suggesting spinal cord pCREB and BDNF may be involved in the development and maintenance of bone cancer pain in mice.