中文摘要：

目的探讨鞘内注射钙／钙调蛋白依赖性蛋白激酶II（CaMKII）抑制剂KN93对骨癌痛小鼠脊髓NR2B蛋白表达的影响及机制。方法SPF级雄性C3J／HeJ小鼠36只，采用随机数字表法分为3组：假手术组（S组n=8）、骨癌痛组（BP组n=8）和KN93组（K组n=20）。BP组和K组采用股骨远端骨髓腔注射20μl含NCTC2472纤维肉瘤细胞的α—MEM的方法制备骨癌痛模型，S组骨髓腔注入不含NCTC2472细胞的同体积α—MEM。K组于接种肿瘤细胞后14d鞘内注射溶于20％DMSO的KN9360nmol／5μl，BP组和S组鞘内注射20％DMSO5μl。分别于肿瘤细胞接种前1d、鞘内注射KN93或溶媒前1h、注射后1，2，4，24h（T0-5）时各组随机取8只小鼠，采用vonFrey丝测定机械痛阈，并于各时点随机取3只小鼠处死取脊髓L3～5节段，采用Westernblot法测定NR2B蛋白的表达。结果与s组[机械痛阈（1．78±0．31）g、NR2B（0．33±0．04）]相比，除K组1r3时机械痛阈差异无统计学意义（P〉0．05）外，BP组[（0．50±0．11）g]和K组[（0．52±0．10）g]机械痛阈均降低（P〈0．05），BP组（1．78±0．34）和K组T2～5[分别为（1．11±0．14）、（0．73±0．03）、（1．11±0．15）、（1．89±0．32）]脊髓组织NR2B蛋白表达均上调（P〈0．05）；与BP组相比，K组T2～4机械痛阈升高，NR2B蛋白表达下调；与给药前T1相比，除K组T2～4机械痛阈升高外，各组各时点该指标差异均无统计学意义（P〉0．05）。结论鞘内注射KN93缓解小鼠骨癌痛的同时降低小鼠脊髓NR2B蛋白表达，CaMKII—NR2B信号通路可能参与了骨癌痛的形成。

英文摘要：

Objective To investigate the effect of KN93,a CaMKII inhibitor,on the spinal NR2B expres- sion in the bone cancer pain mouse and its underlying mechanism. Methods Thirty-six male C3H/HeJ mice were randomly divided into 3 groups： sham group（ S, n = 8） ,bone cancer pain group（ BP, n = 8 ） and KN93 group（ K, n = 20）. The mouse model of bone cancer pain was established by intra-femur inoculation of osteolytic NCTC 2472 cells in BP and K groups. At 14d post operation,mice in K group received intrathecal injection of 60nmol KN93/ 5p,1 in 20% DMSO and mice in BP group and S group received 20% DMSD 5μl respectively. Eight mice were se- lected randomly from each group at 1 d before inoculation, at 1 h before administration and at 1,2,4,24h after ad- ministration（ To_5 ） to be measured the paw withdrawal threshold（PWT） stimulated by von Frey filaments. Another 3 mice were sacrificed at the corresponding time point and the spinal cord L3 -5 were obtained for determination of NR2B expression by western blot. Results PWT was significantly decreased in group BP（ （0.50 ± 0.11 ）g） and K（ （0.52 ±0.10 ） g）, except for group K at T3 （P 〉 0.05 ） , and NR2B expression up-regulated at T2-5 in BP（ 1.78 ±0.34）,Kgroups （（1.11±0.14）,（0.73±0.03）,（1.11 ±0.15）,（1.89±0.32）） compared with S group （（ 1.78 ± 0.31 ）g, （0.33 ± 0.04）, P 〈 0.05 ）. Compared with group BP, PWT was increased and NR2B expres- sion down-regulated at T24 in group K. In contrast to T1 , PWT at T2-4 upgraded in group K （P 〈 0.05 ） , but no sig- nificant difference was observed in other groups（P〉 0.05 ）. Conclusion Intrathecal injection of KN93 can attenu- ate bone cancer pain in mice through inhibiting NR2B with a time-dependent manner and spinal CaMKII-NR2B pathway may participate in the development of bone cancer pain.