右美托咪定通过抑制脊髓小胶质细胞活化减轻吗啡戒断反应痛觉过敏  

Dexmedetomidine alleviates hyperalgesia in morphine withdrawal syndrome by inhibiting microglia activation in spinal cord

作　　者：孔二亮 凤旭东[2] 杨梅 李永畅 袁红斌 KONG Er-liang;FENG Xu-dong;YANG Mei;LI Yong-chang;YUAN Hong-bin(Department of Anesthesiology,The Second Affiliated Hospital of Naval Medical University(Second Military Medical University),Shanghai 200003,China;Department of Anesthesiology,No.988 Hospital of Logistic Support Force of PLA,Zhengzhou 450042,Henan,China)

机构地区：[1]海军军医大学(第二军医大学)第二附属医院麻醉科,上海200003 [2]中国人民解放军联勤保障部队988医院麻醉科,郑州450042

出　　处：《海军军医大学学报》2022年第7期729-735,共7页Academic Journal of Naval Medical University

基　　金：河南省自然科学基金青年项目(222300420384);河南省医学科技攻关计划(SBGJ202003056,SBGJ202102204)。

摘　　要：目的探讨右美托咪定(Dex)对吗啡戒断反应中痛觉过敏的影响及机制。方法 根据药物处理不同将健康雄性C57/BL小鼠随机分为空白对照组、吗啡戒断反应痛觉过敏模型组(M组)、M+Dex组、M+米诺环素(Min)组、M+Dex+Min组、M+MK8825组、M+Min+MK8825组,每组6只。空白对照组小鼠不予任何干预;其他6组小鼠每天上午8:00和下午6:00各腹腔注射吗啡溶液1次,连续注射6 d,随后注射纳洛酮构建吗啡戒断反应痛觉过敏模型。M组为单纯吗啡戒断反应痛觉过敏小鼠,M+Dex、M+Min、M+Dex+Min、M+MK8825、M+Min+MK8825组小鼠在纳洛酮给药前30 min通过鞘内导管分别单次给予人工脑脊液稀释的Dex、小胶质细胞激活抑制剂Min、Dex与Min混合液、降钙素基因相关肽(CGRP)抑制剂MK8825、Min与MK8825混合液。应用von Frey纤维丝测定各组小鼠机械性痛阈,免疫荧光和蛋白质印迹法检测脊髓背角小胶质细胞激活标志物钙离子结合调节因子1(IBA-1)的表达,蛋白质免疫印迹法和PCR检测脊髓背角组织中CGRP蛋白和mRNA表达变化,并用微透析技术测定脊髓背角炎症因子TNF-α、IL-1β水平,最后电生理技术观察Dex对脊髓背角自发性抑制性突触后电流(sIPSC)的影响。结果 成功构建吗啡戒断反应痛觉过敏模型,与空白对照组相比,M组机械性痛阈降低(P<0.05),脊髓背角IBA-1、CGRP表达及TNF-α、IL-1β水平均增加(P均<0.05)。与M组相比,M+Dex、M+Min、M+Dex+Min组机械性痛阈均升高(P均<0.05),脊髓背角IBA-1、CGRP表达及TNF-α、IL-1β水平均降低(P均<0.05)。与M组相比,M+MK8825组脊髓背角TNF-α、IL-1β水平均降低(P均<0.05),而M+MK8825组与M+Min+MK8825组之间TNF-α、IL-1β水平差异均无统计学意义(P均>0.05)。电生理结果显示,与人工脑脊液灌流相比,灌流Dex增强了脊髓背角神经元sIPSC的振幅和频率(P均<0.05)。结论 Dex通过抑制脊髓小胶质细胞激活、减少CGRP表达、减轻脊髓炎症反应及增�Objective To investigate the effect and mechanism of dexmedetomidine(Dex)on hyperalgesia in morphine withdrawal mice.Methods According to drug treatments,healthy male C57/BL mice were randomly divided into blank control group,morphine withdrawal hyperalgesia model group(M group),M+Dex group,M+minocycline(Min)group,M+Dex+Min group,M+MK8825 group,and M+Min+MK8825 group(n=6).No intervention was given to mice in the blank control group.The other 6 groups of mice were intraperitoneally injected with morphine twice a day at 8:00 a.m.and 6:00 p.m.for 6 consecutive days,followed by naloxone injection to establish the morphine withdrawal hyperalgesia model.The M group received no more drugs,while the M+Dex,M+Min,M+Dex+Min,M+MK8825,and M+Min+MK8825 groups were given Dex diluted with artificial cerebrospinal fluid,microglia activation inhibitor Min,Dex and Min mixture,calcitonin gene-related peptide(CGRP)inhibitor MK8825,and Min and MK8825 mixture through intrathecal catheter 30 min before naloxone administration,respectively.Mechanical pain thresholds were tested by von Frey.The expression of microglia activation marker ionized calcium-binding adapter molecule 1(IBA-1)in the spinal dorsal was observed by immunofluorescence and Western blotting.The expression of CGRP protein and mRNA in the spinal cord of each tissue was detected by Western blotting and polymerase chain reaction(PCR).The levels of inflammatory factors tumor necrosis factorα(TNF-α)and interleukin-1β(IL-1β)in the spinal cord were determined by microdialysis.Finally,the effect of Dex on spontaneous inhibitory postsynaptic current(sIPSC)in the spinal dorsal horn was observed by electrophysiology.Results The morphine withdrawal hyperalgesia model was successfully established.Compared with the blank control group,the mechanical pain threshold in the M group was significantly decreased(P<0.05),and the expression of IBA-1,CGRP and the levels of TNF-αand IL-1βin the spinal dorsal horn were significantly increased(all P<0.05).Compared with the M group,the pain

关 键 词：右美托咪定 吗啡 痛觉过敏 小胶质细胞 降钙素基因相关肽 脊髓背角 

分 类 号：R441.1[医药卫生—诊断学]