挥发性有机物混合暴露对小鼠脑组织的氧化损伤及学习记忆能力的影响

为探讨挥发性有机物混合急性暴露对小鼠脑组织氧化损伤及学习记忆能力的影响,选用雄性昆明种小鼠50只,随机分为对照组和4个染毒组。1到4号染毒组中甲醛、苯、甲苯和二甲苯浓度依次为:(1.0+1.1+2.0+2.0)、(3.0+3.3+6.0+6.0)、(5.0+5.5+10.0+10.0)、(10.0+11.0+20.0+20.0)mg·m~(-3)。各染毒组混合气体组分的浓度分别是我国室内空气质量标准(GB/T18883—2002)的10、30、50和100倍。结果显示,在Morris水迷宫实验第4天,2、3和4号染毒组小鼠的逃避潜伏期分别为(68.9±10.3)、(72.2±4.0)和(71.5±5.1)s,比对照组(48.5±10.1)s显著延长(P<0.05或P<0.01),但小鼠的脑体比和抓力在染毒期间没有明显变化。同时,随着染毒剂量的增加,小鼠脑组织中GSH含量显著降低,ROS和MDA含量显著升高。研究表明,挥发性有机物混合暴露可导致小鼠学习记忆能力降低,而脑组织氧化损伤可能是引起神经毒性,导致学习记忆能力降低的原因之一。

Oxidative Damage in Brain Tissue Induced by Exposure to Mixture of Volatile Organic Compounds and Its Effects on Learning and Memory Abilities of Mice

To study the oxidative damage to brain tissue and effects on learning and memory abilities of mice after the acute inhalation of mixture of volatile organic compounds（VOCs）,50 Kunming male mice were randomly divided into one control group and four exposure groups,and the concentrations of formaldehyde,benzene,toluene and xylene of exposure group No.1 to No.4 were as follows:（1.0 +1.1 +2.0 +2.0）,（3.0 +3.3 +6.0 +6.0）,（5.0 +5.5 +10.0 +10.0）,（10.0 +11.0 +20.0 +20.0） mg·m^-3,which corresponded to 10,30,50 and 100 times of Chinese indoor air quality standards（GB/T 18883-2002）,respectively.Results showed that on the 4th day of Morris water maze experiment,escape latency of group No.2,No.3 and No.4 were（68.9±10.3）,（72.2±4.0） and（71.5±5.1） s,and they were all significantly longer than the control group（（48.5±10.1） s）（P <0.05 or P <0.01）.However,the brain-to-body mass ratio and grip strength did not show significant changes in all exposure groups.Moreover,when exposure dose increased,the significant decrease of GSH level,and the significant increase of levels of ROS and MDA in mouse brain were all observed.Thus,it is deduced that inhalation of VOC mixture could cause the damage to learning and memory abilities of mice.Oxidative damage in brain was one of the possible reasons to induce neurotoxicity and affect learning and memory of mice.