MA与HIV-Tat协同作用致大鼠相关脑区ROS、GSH-PX和SOD的变化

Changes of ROS、GSH-PX and SOD induced synergistically by MA and HIV-Tat in certain cerebral regions in rats

目的观察甲基苯丙胺(MA)与HIV-Tat蛋白协同作用致大鼠相关脑区活性氧(ROS)、谷胱甘肽过氧化物酶(GSH-PX)和超氧化物歧化酶(SOD)的变化,探讨协同作用对神经系统的影响。方法 50只健康雄性SD大鼠随机分为实验组:MA组(10mg/kg MA,每日两次腹腔注射,连续4d)、HIV-Tat组(10μg HIV-Tat注入大鼠脑纹状体)和MA+HIV-Tat组(按MA组注射MA 4d后按HIV-Tat组注入HIV-Tat);对照组:生理盐水腹腔注射或纹状体内注射。各组大鼠分别于注射结束后48h和7d处死,取各脑区脑组织制作匀浆;荧光分光光度计检测ROS含量,酶标仪检测GSH-PX和SOD吸光度,再根据蛋白质的浓度分别计算其活力。结果各实验组与对照组比较,各脑区ROS含量有不同程度增高,GSH-PX和SOD活力则有不同程度下降,差异具有统计学意义(P<0.05);其中MA+HIV-Tat组与MA组和HIV-Tat组比较,ROS含量升高显著,GSH-PX和SOD活力下降明显(P<0.01)。结论 MA和HIV-Tat协同作用能够产生大量的ROS,并降低GSH-PX和SOD的活力,揭示ROS、GSH-PX和SOD参与了MA与HIV-Tat的协同神经毒性作用。

Objective To observe changes of reactive oxygen species（ROS）,glutathione peroxidase（GSH-PX） and superoxide dismutase（SOD） in certain rat brain regions and investigate the effects of nervous system induced synergistically by MA and HIV-Tat protein.Methods In this experiment,50 healthy male SD rats were randomly divided into MA group（received intraperitoneal injection of 10mg/kg MA,twice per day for 4 days）,HIV-Tat group（received intra-striatal injection of 10μg HIV-Tat） and MA＋HIV-Tat group（intraperitoneal injection of MA,followed by intra-striatal injection of HIV-Tat）,and control groups（intraperitoneal or intra-striatal injection of saline,or both）.The rats were killed at 48h or 7 days after the last time of injection.The cerebral regions were separated and homogenated.ROS content was measured by fluorescence spectrophotometry.GSH-PX and SOD were determined by ELIASA.GSH-PX and SOD activities were calculated according to protein concentration.Results As compared with the control groups,ROS contents in the cerebral regions were increased,whereas GSH-PX and SOD activity was significantly reduced in the MA group and HIV-Tat group（P0.05）.Compared with MA group or HIV-Tat group,ROS content was increased more evidently,and GSH-PX and SOD activities were lowered significantly in MA＋HIV-Tat group（P0.01）.Conclusion MA and HIV-Tat interact synergistically to produce more ROS with concomitant reduction of GSH-PX and SOD activities,suggesting a collaborating neurotoxicity.