鞘内注射ERK1/2抑制剂对骨癌痛大鼠的镇痛作用研究

摘要

目的 研究鞘内注射细胞外调节蛋白激酶(ERK1/2)抑制剂(SCH772984)对骨癌痛Sprague-Dawley(SD)大鼠疼痛行为学及脊髓背角Fos蛋白表达的影响,探讨ERK-P90RSK-Fos信号通路在骨癌痛中的作用.方法 取鞘内置管后5天的雌性SD大鼠40只,随机分成5组(n=8),包括Sham假手术组和BNP模型组(分别为对照组,SCH772984给药组SCH 0.1组,SCH 1组,SCH 10组).在造模后第9天,Sham组不给药,BNP模型组鞘内分别给5％ DMS0 10μl、SCH772984抑制剂0.1、1.0、10μg(SCH772984抑制剂溶于10μl 5％的DMSO中).测定造模前1天、造模后3、6、9、12、15、18天以及给药后1、3、6、9、12、18、24h的机械缩足阈值(MWT)、热缩足潜伏期(PWL)以及2min自发缩足次数.取鞘内置管后5天的SD大鼠40只,随机分为5组(n=8),其中B1、B2、B3组在造模后第9天,鞘内注射SCH772984抑制剂10μg后分别于1、9、24h取材,M组为模型对照组,鞘内注射5％ DMSO后9h取材,S组为空白对照组.通过免疫印迹(Western blot)法及免疫荧光测定脊髓背角p-ERK、p-p90RSK以及Fos蛋白表达情况.结果 鞘内注射ERK1/2抑制剂(SCH772984)对骨癌痛大鼠有镇痛作用,并且该效应随着剂量的增加而增大;鞘内注射ERK1/2抑制剂(SCH772984) 10μg可明显减少脊髓背角Fos蛋白的表达.结论 ERK-p90RSK-Fos通路可能影响骨癌痛.%Objective To investigate the effect of Intrathecal injection of ERK1/2 inhibitor (SCH772984) on the behaviors of analgesic effect in rat with bone cancer pain and the expression of Fos protein in spinal dorsal horn,and the role of ERK-P90RSK-Fos signaling pathway played on rat with bone cancer pain.Methods Forty female SD rats after taken intrathecal catheter were randomly divided into five group (Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ) (n =8).Sham-operated group (Ⅰ),BNP model groups (Control group and different dosage group:SCH 0.1 group,SCH 1 group,SCH 10 group).Nine day after model establishment,group Ⅰ was treated without drug,group Ⅱ,Ⅲ,Ⅳ,Ⅴ were treated with 5％ DMSO 10μl,SCH772984 inhibitor 0.1,1.0 and 10μg(SCH772984 inhibitor melted in 10μl 5％ 的 DMSO).Mechanical withdrawal threshold (MWT),thermal withdrawal latency (PWL) and spontaneous flinching times (2 mninutes) were measured before model establishment (1day) and before model establishment (3,6,9,12,15 and 18 day) and treated with drug (1,3,6,9,12,18 and 24h).40 female SD rats after taken intrathecal catheter were randomly divided into five group (B1,B2,B3,M and S) (n =8).B1,B2 and B3 groups treated with model establishment (9 day).Intrathecal injection was performed with SCH772984 inhibitor 10μg and samples was collected in 1,9 and 24h.M group was model group.Intrathecal injection was performed with 5％ DMSO and samples was collected in 9h.S group was blank group.Western blot and immunofluorescence were used to detect the protein expression of p-ERK,p-p90RSK and Fos.Results Intrathecal injection of ERK1/2 inhibitor can play roles of analgesic effect in rats with bone cancer pain,and the effect increased with the increase of the ERK1/2 inhibitor dose.Intrathecal injection of ERK1/2 inhibitor (SCH772984) 10μg can significant decreased the protein expression of Fos in spinal dorsal horn.Conclusion ERK-p90RSK-Fos signaling pathway can participate in the regulation of bone cancer pain.