地西泮结合抑制因子基因在慢性吗啡依赖大鼠部分脑区的表达

Expressions of diazepam binding inhibitor in some selected brain regions of chronic morphine dependent rats at different time-points

目的研究地西泮结合抑制因子(DBI)基因在慢性吗啡依赖大鼠部分脑区不同时点表达水平的变化。方法30只雄性SD大鼠随机分为研究组20只和生理盐水对照组10只。研究组:腹腔注射盐酸吗啡,2次/d,起始剂量为5mg·kg1·次1,逐日递增5mg·kg1·次1,至第10天为50mg·kg1·次1,对照组同期注射相同体积的生理盐水。研究组于末次注射后3h(依赖组)及72h(戒断3d组)、第6天(戒断6d组)、第10天(戒断10d组)分别处死5只,对照组于末次注射后3h及72h分别各处死5只,灌注、取脑、冰冻切片并选取含有海马CA1区(HIPCA1)、中脑腹侧被盖区(VTA)、伏隔核(Nac)、前额叶皮质(PFC)、杏仁核(AMG)、中脑导水管(PAG)等结构的脑片,利用组织原位杂交技术检测DBImRNA在各脑区的表达,进行组间比较。结果吗啡成瘾组在HIPCA1、VTA、NAc、PFC、AMG、PAG和LC的DBImRNA表达依次为:102.7±6.7、139.6±12.8、137.1±9.3、144.3±10.8、153.6±10.6、122.1±8.5和100.0±8.8,显著高于对照组,并均在戒断的第3天达到峰值,依次为139.7±12.4、181.1±10.2、159.3±13.3、186.6±7.6、195.1±7.0、176.9±14.7,随后出现下调,在戒断第6天各脑区仍高于对照组,在戒断第10天,除了PFC仍为145.3±9.3,明显高于对照组(P<0.05)外,其他脑区与对照组无显著差异。

ObjectiveTo explore the changes of expression of diazepam binding inhibitor (DBI) gene in some defined brain loci of rats at the selected time points after chronic morphine administration. MethodsThirty male Sprague Dawley (SD) rats were randomly assigned into six groups, including four study groups and two control groups, according to the executed time points after the final administration. Rats in experiment group were intraperitoneally administrated with morphine, twice a day for ten days, in an ascending dosage schedule, to the 50mg/kg per dose at the tenth day increasing 5mg/kg per dose per day, correspondingly rats in control groups were injected with same volume saline. rats were scarified at the corresponding time points, and the brains were removed, then the mRNA levels of DBI in the regions of ventral tegmental area (VTA),nucleus accumben (NAc), the CA1 of hippocampus (HIPCA1), prefrontal cortex(PFC),amygdala (AMG), periaqueductal gray (PAG),Locus coeruleus(LC) were estimated with in situ hybridization and compared between groups.ResultsThe mean levels of expression of the DBI in different regions significantly increases in 3h group, reached the peak level at 3 day after the end of morphine administration group, then decreased. At the ten day of discontinuation of treatment the expressed levels came to the baseline in VTA, NAc, HIPCA1, AMG and PAG,but in PFC it is still higher than control group. ConclusionThe up regulation of DBI mRNA following chronic morphine administration and withdrawal maybe the one of molecular mechanism underlying opiate dependence and withdrawal.