摘要目的：观察鞘内注射P2Y12受体抑制剂MRS2395对骨癌痛大鼠痛阈及其脊髓炎症因子表达的影响，探讨P2 Y12受体与炎症因子在骨癌痛发病机制中的可能作用。方法雌性SD大鼠32只，随机数字表法随机分为4组：假手术组（ S组）、MRS2395组（ M组）、胫骨癌痛组（ A组）、胫骨癌痛MRS2395组（ MA组）。 S组、M组左胫骨上端骨髓腔各注入Hank′s液10μl，A组、MA组左胫骨上端骨髓腔各注入Walker256癌细胞悬液10μl。骨癌痛造模同时均进行L3-4间隙鞘内置管，模型制备成功后第9～12天， S 组、A 组鞘内注射0.9％生理盐水15μl/d， M 组、MA 组鞘内注射 MRS2395（400 pmol/μl）15μl/d。术后第9～12天鞘内注药前、后每10分钟测试1次大鼠左后足机械痛阈值，术后第12天鞘内注药测定机械痛阈值后，取L4-L6左侧脊髓背角，采用酶联免疫吸附测定法测脊髓炎症因子IL-1β、IL-6的表达情况。结果建模后第9天，S组、M组、A组、MA组给药后20 min机械痛阈值分别为（34.2±5.8）g、（34.4±5.7）g、（21.0±2.0）g、（25.4±2.3）g，差异有统计学意义（F＝18.679，P＜0.01）；与S组、M组比较，A组机械痛阈值下降；与A组比较，MA组机械痛阈值增高。建模后第12天，S组、M组、A组、MA组大鼠脊髓IL-1β含量分别为（74.0±18.6）pg/ml、（98.4±17.3） pg/ml、（253.5±66.4）pg/ml、（146.3±22.3） pg/ml，差异有统计学意义（F＝18.221，P＜0.01）；与S组、M组比较，A组大鼠脊髓IL-1β含量明显升高；S组、M组、A组、MA组大鼠脊髓IL-6含量分别为（377.4±65.8）pg/ml、（331.6±67.9） pg/ml、（856.1±53.4） pg/ml、（596.1±34.9） pg/ml，差异有统计学意义（F＝70.880，P＜0.01）；与S组、M组比较，A组大鼠脊髓IL-6含量明显升高；与A组比较， MA组大鼠鞘内注射MRS2395后IL-1β和IL-6含量均明显降低。结论鞘内注射MRS2395可缓解骨癌痛大鼠的痛觉过敏，抑制骨癌痛大鼠脊髓内炎症因子表达上调，P2Y12受体可能通过调节IL-1β、IL-6的表达参与骨癌痛的发生。

abstractsObjective To explore the roles of P2Y12 receptor ( P2Y12R) in bone cancer pain by observing the changes of inflammatory cytokines (IL-1β, IL-6) after intrathecal injection (i.t.) of P2Y12R antagonist MRS2395.Methods Thirty-two female SD rats were randomly divided into 4 groups ( n =8 each):sham group (group S), MRS2395 group (group M), cancer group (group A) and cancer +MRS2395 group ( group MA).Groups S and M received an injection of 10 μl Hank′s solution into left tibia medullar cavity while groups A and MA had an injection of Walker 256 mammary cancer cells (10 μl, 2 × 107 cells/ml) into the same place.At Day 9-12 post-inoculation, groups S and A received an injection of saline (0.9%, 15 μl, i.t.) while groups M and MA had MRS2395 (400 pmol/μl, 15 μl, i.t.).Intrathecal catheterization between L 3 and L4 was performed immediately after inoculating tumor cells by inserting a small tube into vertebral space.Mechanical withdrawal thresholds were measured on left hind paws before and during 10-minute intervals after dosing.Spinal cords ( L4-L6 segments ) were removed for determining the expressions of IL-1βand IL-6 by enzyme-linked immunosorbent assay ( ELISA ) at Day 12 after drug delivery.Results At 20 min post-injection, mechanical withdrawal thresholds of groups S , M, A and MA were (34.2 ±5.8), (34.4 ±5.7), (21.0 ±2.0) and (25.4 ±2.3) g respectively at Day 9 post-inoculation ( F=18.679, P <0.01 ); mechanical withdrawal thresholds of group A obviously decreased versus groups S and M;mechanical withdrawal thresholds in group MA increased obviously versus group A.The expressions of IL-1βin groups S , M, A and MA were ( 74.0 ±18.6 ) , ( 98.4 ±17.3 ) , ( 253.5 ± 66.4) and (146.3 ±22.3) pg/ml at Day 12 post-inoculation (F=18.221, P<0.01); compared with groups S and M, the expression of IL-1βin group A showed a significant up-regulation.Likewise, the expressions of IL-6 were (377.4 ±65.8), (331.6 ±67.9), (856.1 ±53.4) and (596.1 ±34.9) pg/ml (F=70.880, P<0.01) respectively in groups S, M, A and MA; compared with groups S and M, the expression of IL-6 increased obviously in group A.There were significant decreases of IL-1βand IL-6 in group MA versus group A .Conclusions An intrathecal injection of MRS 2395 may alleviate hyperalgesia and inhibit the up-regulated expression of spinal cord inflammatory cytokines in bone cancer rats.And P2Y12 receptor may be involved in the formation of bone cancer pain through regulating the expressions of IL-1βand IL-6.