吗啡成瘾大鼠四个脑区μ阿片受体的变化  

Changes ofμopioid receptor in four brain regions of rats addicted to morphine

作　　者：孙雪峰[1] 王新华[1] 傅强[1] 石学银[1] 

机构地区：[1]第二军医大学长征医院麻醉科,上海200003

出　　处：《第二军医大学学报》2002年第2期150-152,共3页Academic Journal of Second Military Medical University

基　　金：国家自然科学基金资助项目 (39870 757)

摘　　要：目的 :观察吗啡成瘾大鼠下丘脑、额叶皮质、海马和纹状体内μ阿片受体数量和基因表达的变化。方法 :剂量递增腹腔注射吗啡建立大鼠成瘾模型 ,断头处死大鼠后分离四个脑区 ,以 3H - DAGO为标记配体进行放射配体测定 ;以β- actin为内参照进行 RT- PCR。结果 :腹腔注射吗啡 9d后成功建立成瘾大鼠模型。在放射配体实验中 ,对照组下丘脑、额叶皮质、海马、纹状体的μ受体数量 (fm ol/ mg)分别为 12 6 .5± 2 7.9、12 2 .6± 2 1.2、135 .3± 12 .6、178.7± 2 6 .7;在成瘾组分别为 76 .9± 2 7.3、95 .9± 2 0 .1、6 7.8± 15 .6、138.9± 19.8,较对照组显著下降 (P<0 .0 5 )。 RT- PCR结果显示 ,对照组下丘脑、额叶皮质、海马、纹状体内μ受体 m RNA表达量分别为 9.3± 1.2、3.2± 0 .8、3.7± 0 .3、5 .0± 1.7;成瘾组分别为 1.0± 0 .7、2 .5± 1.1、1.3± 0 .5、1.7± 0 .8,除额叶皮质外均较对照组显著降低 (P<0 .0 5 )。结论 :大鼠在吗啡成瘾过程中脑内出现 μ受体基因表达的下降和 μ受体的下调。推测 μ受体的下调可能是引起吗啡成瘾的原因之一 。Objective:To observe the changes of quantity and gene expression ofμ opioid receptor in hypothalam us, frontal cortex,hippocam pus and striatum in m orphine addiction rats.Methods:Rats were adm inistered with morphine by intraperitoneal injection with increasing dose to develop addiction model.Four brain regions were subjected to radioligand assay and reverse transcription- polym erase chain reaction (RT- PCR) study.3H- DAGO was used in radioligand assay andβ- actin was used as control gene in RT- PCR study.Results:Rat addiction model was developed after 9d morphine injection.In radioligand assay,the3H - DAGO binding of hypothalamus,frontal cortex,hippocampus and striatum was 12 6 .5± 2 7.9,12 2 .6 ± 2 1.2 ,135 .3± 12 .6 ,178.7± 2 6 .7fm ol/ mg protein respectively in control group,but decreased significantly to 76 .9± 2 7.3, 95 .9± 2 0 .1,6 7.8± 15 .6 ,138.9± 19.8fm ol/ mg in addiction group(P <0 .0 5 ) .In RT- PCR study,m RNA level ofμ opioid receptor in addiction group decreased significantly in the studied brain regions except frontal cortex.m RNA level of hypothalamus,frontal cortex,hippocam pus and striatum was 9.3± 1.2 ,3.2± 0 .8,3.7± 0 .3,5 .0± 1.7in control group,but 1.0± 0 .7,2 .5± 1.1,1.3± 0 .5 ,1.7± 0 .8respectively in addiction group.Conclusion:Both binding and expression ofμ opioid receptor decrease significantly in morphine addiction rats.The downregulation ofμ opioid receptor,which is related to lower gene expression,may be one of the causes of m orphine addiction. [

关 键 词：麻醉品依赖 放射配位体测定 基因表达 吗啡成瘾 大鼠 Μ阿片受体 

分 类 号：R595.5[医药卫生—内科学]