【作者】 蒋惠萍；

【导师】 余艳红； 陈敦金；

【作者基本信息】 南方医科大学 ， 病理生理学， 2008， 博士

【摘要】 多溴联苯醚(PBDEs)是一系列含溴原子的芳香族化合物。根据苯环上溴原子的个数和位置的不同,多溴联苯醚总共有209种同分异构体。可以作为阻燃剂添加入多种电子产品、塑料泡沫、装饰材料等产品之中。当这些产品报废后不经过严格的回收和后期处理,而随意废置于自然界,产品中的化学阻燃剂成分将进入人类的生存环境,且难以降解,形成持续性有机污染物。通过水气挥发、空气流动等途径在环境中传播,并进入食物链,易在生物体包括人体的脂肪组织中聚集,对人类及整个生态系统造成潜在危害。由于PBDEs结构类似于PCBs(多氯联苯醚,目前已被禁止生产使用)和甲状腺激素(生物神经发育过程中的关键激素之一),从PBDEs开始使用至今,对其毒性的研究一直受到人们的关注。以往研究主要为低溴类如BDE-99,47,153等,结果发现其生物毒性明显,可导致内分泌紊乱,神经行为失常,其某些代谢物可能具有致癌性等。在母胎医学领域,目前认为PBDEs可以通过胎盘屏障和血脑屏障等进入胎儿体内或进入脑组织,以致胎儿脑组织的发育不良,因此在美国以及欧洲等地相继被限制生产及使用。BDE-209是PBDEs家族中含溴最高的一种化合物,在全球范围内使用广泛。在中国,空气、水以及河流沉淀物中BDE-209的含量均高于西方国家同期水平。由于目前对BDE-209的毒性不确定,所以世界范围内仍在使用。现有的实验资料表明的观点有两种:(1)BDE-209对生物体是有害的,包括神经发育毒性,免疫毒性,内分泌毒性以及致癌性等,应该像低溴的阻燃剂一样被限制生产使用:(2)由于BDE-209在体内的代谢快,蓄积低,在常规暴露水平下对机体不造成影响。由于研究结果不一致,到目前为止,BDE-209对生物毒性影响依然未定。本课题组在2006-2007年已通过实验证实母源性BDE-209暴露可造成仔鼠学习记忆能力下降,提示BDE-209具有神经发育毒性。但BDE-209神经发育毒性的量效关系及其作用机制的研究尚未深入。本课题根据BDE-209脂溶性强,环境含量高,生物暴露量大,具有生物累积及生物放大效应的特点,建立不同剂量BDE-209的母源性暴露动物模型,研究母源性BDE-209暴露对仔鼠海马结构功能的影响及与染毒剂量的关系,初步探讨BDE-209神经发育毒性的作用机制。本课题将分为以下五个部分进行各项具体实验。第一章母源性BDE-209暴露对仔鼠学习记忆能力及海马组织结构的影响【目的】建立不同剂量BDE-209的母源性暴露动物模型,观察仔鼠海马组织结构形态学的改变,并对仔鼠学习记忆能力进行检测。观察母源性BDE-209暴露对仔鼠海马结构功能的影响及与剂量的关系。【材料与方法】1.建立动物模型:购买3月龄SPF级wistar雌鼠50只,雄鼠25只。分笼饲养7天后,按雌:雄2:1比例合笼,自雌鼠妊娠0天起,随机分为五组:实验组(A):孕哺期胃灌母鼠BDE-209(100mg/kg.d);实验组(B):孕哺期胃灌母鼠BDE-209(300mg/kg.d);实验组(C):孕哺期胃灌母鼠BDE-209(600mg/kg.d);实验组(D):孕哺期胃灌母鼠BDE-209(1200mg/kg.d);对照组(E):孕哺期胃灌母鼠等量花生油。每日一次。2.Morris水迷宫测试:仔鼠断乳后1周,根据随机数字表法各组随机选取雄性仔鼠20只,进行水迷宫试验,共8天,前3天训练,后5天记录成绩做为测试结果。每天上午、下午各1次。观察仔鼠学习记忆能力的变化。3.制作病理切片:水迷宫试验结束后,各组随机选取5只仔鼠,予4%多聚甲醛及生理盐水进行心脏灌注固定后,取海马组织4%多聚甲醛固定24小时,经过洗涤、脱水、浸蜡、包埋、切片与粘片、脱蜡、染色、脱水、透明、封片等步骤后制成病理切片,光镜下观察海马组织结构形态学变化。【结果】1.水迷宫试验结果:第1天,D组与E组比较差异有统计学意义(P=0.029),A、B、C组与E组比较差异无统计学意义(P=0.303,P=0.146,P=0.077)。第2天,C、D组与E组比较差异有统计学意义(P=0.041,P=010),A、B组与E组比较差异无统计学意义(P=0.163,P=0.235)。第3-5天时,B、C、D组与E组比较差异有统计学意义,P值均小于0.05。A组与E组比较差异无统计学意义,P值均大于0.05。A组与D组比较差异有统计学意义,P值均小于0.05。提示:实验组潜伏期较对照组显著延长,低剂量(100mg/kg.d)母源性BDE-209暴露对仔鼠空间学习记忆能力无明显影响;高剂量母源性(BDE-209≥300mg/kg.d)暴露可导致仔鼠学习记忆能力下降。2.HE染色后光镜下观察仔鼠海马组织结构变化:C、D组仔鼠海马组织形态学变化明显,神经元排列紊乱,数量明显减少,细胞皱缩,核固缩过半,细胞间质水肿。A、B组变化不明显。【结论】高剂量母源性BDE-209暴露可以影响仔鼠学习记忆能力,破坏仔鼠海马组织结构。提示BDE-209具有神经毒性,影响神经系统发育,并且具有显著的剂量-效应关系。第二章母源性BDE-209暴露对仔鼠海马CaMKⅡ、BDNF及GAP-43的影响【目的】CaMKⅡ、GAP-43及BDNF是与神经系统发育至关重要的特异性蛋白,对神经系统的发育及其神经元之间信号的传导起着重要调控作用,包括神经元的生长、分化及突触形成。海马是与学习记忆相关的重要脑区。我们通过观察母源性BDE-209暴露后仔鼠海马CaMKⅡ、GAP-43及BDNF的变化,探讨母源性BDE-209对仔鼠神经发育相关蛋白的影响。【材料与方法】1.水迷宫试验结束后,各组随机选取10只仔鼠,断头处死,在冰帽上快速分离海马,置于液氮中保存。制成组织匀浆后,用ELISA法检查海马CaMKⅡ活性。2.各组随机选取5只仔鼠,予4%多聚甲醛及生理盐水进行心脏灌注固定后,取海马组织4%多聚甲醛固定24小时,制作石蜡切片,用免疫组织化学法检测BDNF及GAP-43在海马组织中的表达。【结果】1.仔鼠海马CaMKⅡ含量的测定:各组组间比较提示组间差异有统计学意义,F=2.868,P=0.034。其中,C、D组与E组比较差异有统计学意义(P=0.031,P=0.005),A、B组与E组比较差异无统计学意义(P=0.526,P=0.284)。各实验组间比较,A组与D组差异有统计学意义(P=0.025),B、C组与D组比较差异无统计学意义(P=0.068,P=0.474)。提示:一定剂量母源性(BDE-209≥600mg/kg.d)暴露可导致仔鼠海马CaMKⅡ含量下降。2.仔鼠海马GAP-43的表达:组间比较提示差异有统计学意义,F=4.854,P=0.007。C、D组与E组比较,差异有统计学意义(P=0.013,P=0.000),A、B组和E组比较差异无统计学意义(P=0.177,P=0.093)。A、B组与D组比较差异有统计学意义(P=0.011,P=0.025)。C组和D组比较差异无统计学意义(P=0.157)。提示:一定剂量母源性(BDE-209≥600mg/kg.d)暴露可导致仔鼠海马GAP-43表达显著下降。3.仔鼠海马BDNF的表达:组间比较提示差异有统计学意义,F=4.540,P=0.009。B、C、D组与E组比较差异有统计学意义(P=0.033,P=0.005,P=0.001),A组和E组比较差异无统计学意义(P=0.066)。A、B、C组与D组比较差异无统计学意义(P=0.052,P=0.103,P=0.409)。提示:一定剂量母源性(BDE-209≥300mg/kg.d)暴露可导致仔鼠海马BDNF表达显著下降。【结论】高剂量母源性BDE-209暴露可以降低仔鼠海马CaMKⅡ的含量及GAP-43、BDNF的表达,从而影响神经元的生长、发育及突触形成,对其功能的发挥造成损伤。第三章母源性BDE-209暴露对仔鼠海马SOD活性及MDA含量的影响【目的】外源性化学物诱发自由基反应,扰乱机体的氧化与抗氧化平衡状态,从而产生相应的链式反应,导致机体功能紊乱已成为化学物质重要毒性机制,且氧化应激学说在神经毒性机制研究中占有重要地位。我们通过观察母源性BDE-209暴露后仔鼠海马SOD活性及MDA含量的变化,探讨BDE-209神经毒性的作用机制。【材料与方法】1.水迷宫试验结束后,各组随机选取10只仔鼠,断头处死,剥出全脑,掀开大脑皮层,用眼科镊小心分离海马组织,4℃生理盐水漂洗去血液,放入冻存管,立即置于液氮内保存。2.采用黄嘌呤氧化法测定SOD,以每毫克海马组织蛋白在1 ml反应液中SOD抑制率达50%时所对应的SOD量为一个亚硝酸盐单位(U/mgprot);硫代巴比妥酸法测定MDA,以nmol/mgprot表示;考马斯亮兰法测定海马中蛋白含量。用550nm分光光度计测定其OD值,并计算各组仔鼠海马组织中SOD的活力和MDA的含量。【结果】1.仔鼠海马SOD活性测定:各组组间比较提示差异有统计学意义,F=5.332,P=0.001。与对照组比较,C组与E组比较,差异有统计学意义(P=0.016),D组与E组比较,差异有统计学意义(P=0.000)。A、B组与E组比较差异无统计学意义(P=0.180,P=0.068)。实验组间比较,A组与D组比较差异有统计学意义(P=0.003),B组与D组比较差异有统计学意义(P=0.013)。C组与D组比较差异无统计学意义(P=0.059)。提示:一定剂量母源性(BDE-209≥600mg/kg.d)暴露可导致仔鼠海马SOD活性显著下降。2.仔鼠海马MDA含量测定:各组组间比较提示差异有统计学意义,F=6.630,P=0.000。与对照组比较,C组与E组比较,差异有统计学意义(P=0.000),D组与E组比较,差异有统计学意义(P=0.000)。A、B组与E组比较差异无统计学意义(P=0.407,P=0.081)。实验组间比较,A组与D组比较差异有统计学意义(P=0.001),B组与D组比较差异有统计学意义(P=0.014)。C组与D组比较差异无统计学意义(P=0.451)。提示:一定剂量母源性(BDE-209≥600mg/kg.d)暴露可导致仔鼠海马MDA含量明显升高。【结论】高剂量母源性BDE-209暴露可以使仔鼠海马SOD活力下降,MDA含量升高,出现氧化应激状态,干扰氧化与抗氧化平衡系统,导致氧化损伤,破坏神经系统的结构与功能。氧化应激可能是母源性BDE-209神经毒性作用机制之一。第四章母源性BDE-209暴露对仔鼠海马Bax、Bcl-2mRNA表达的影响【目的】神经系统发育过程中,细胞凋亡对于维持细胞总体数量具有重要的作用,是许多神经损伤后神经细胞死亡的主要方式,与脑功能受损密切相关。我们通过观察母源性BDE-209暴露后仔鼠海马凋亡基因Bax、Bcl-2 mRNA表达的变化,探讨BDE-209对神经细胞凋亡的影响。【材料与方法】1.水迷宫试验结束后,各组随机选取5只仔鼠,断头处死,在冰帽上快速分离海马,置于液氮中保存。2.提取海马总RNA,紫外分光光度法测RNA浓度及纯度;2.设计引物及合成(分别设计并合成Bcl-2及Bax mRNA的引物);3.逆转录及荧光定量PCR反应;4.制备阳性标准模板;5.PCR产物琼脂糖凝胶电泳。【结果】1.仔鼠海马Bcl-2 mRNA表达的变化:各组组间比较提示差异有统计学意义,F=3.628,P=0.022。与对照组比较,C组与E组比较差异有统计学意义(P=0.011),D组与E组比较差异有统计学意义(P=0.005),A、B组与E组比较差异无统计学意义(P=0.459,P=0.167),A组与D组比较差异有统计学意义(P=0.025)。提示:一定剂量母源性暴露(BDE-209≥600mg/kg.d)可导致仔鼠海马Bcl-2 mRNA表达下调。2.仔鼠海马Bax mRNA表达的变化:各组组间比较提示差异有统计学意义(F=3.785,P=0.019)。与对照组比较,C组与E组比较差异有统计学意义(P=0.032),D组与E组比较差异有统计学意义(P=0.002),A、B组与E组比较差异无统计学意义(P=0.525,P=0.174),A组与D组比较差异有统计学意义(P=0.010)。提示:一定剂量母源性暴露(BDE-209≥600mg/kg.d)可导致仔鼠海马Bax mRNA表达上调。3.仔鼠海马Bcl-2/Bax mRNA的比较:各组组间比较提示差异有统计学意义,F=6.003,P=0.002。与对照组比较,C、D组与E组比较差异有统计学意义(P=0.032,P=0.000),A、B组与E组比较差异无统计学意义(P=0.356,P=0.076),A组与D组比较差异有统计学意义(P=0.004),B组与D组比较差异有统计学意义(P=0.031)。提示:一定剂量母源性暴露(BDE-209≥600mg/kg.d)后仔鼠海马Bcl-2/Bax mRNA比率下降。【结论】母源性BDE-209暴露后仔鼠海马区Bcl-2 mRNA表达下调,Bax mRNA表达上调,并具有剂量-效应关系。提示:母源性BDE-209暴露可引起仔鼠海马神经元细胞凋亡,Bcl-2和Bax可能参与调控了细胞凋亡过程,母源性BDE-209暴露引起仔鼠海马神经元细胞凋亡异常及其调控基因的变化可能是其导致仔鼠学习记忆障碍的重要机制之一。全文小结1.母源性BDE-209暴露可以导致仔鼠学习记忆能力下降,仔鼠海马组织形态结构发生明显改变。提示BDE-209具有神经毒性,影响神经系统发育,并且具有显著的剂量-效应关系。2.母源性BDE-209暴露可以降低仔鼠海马CaMKⅡ的含量及GAP-43、BDNF的表达,从而影响神经元的生长、发育及突触形成,对其功能的发挥造成损伤。3.母源性BDE-209暴露可以使仔鼠海马SOD活性下降,MDA含量升高,出现氧化应激状态,干扰氧化与抗氧化平衡系统,导致氧化损伤,破坏神经系统的结构与功能。氧化应激可能是母源性BDE-209暴露神经发育毒性作用机制之一。4.母源性BDE-209暴露后仔鼠海马区Bcl-2 mRNA表达下调,Bax mRNA表达上调,Bcl-2/Bax mRNA的比率下降。并具有剂量-效应关系。提示:母源性BDE-209暴露可引起仔鼠海马神经元细胞凋亡,Bcl-2和Bax可能参与调控了细胞凋亡过程,母源性BDE-209暴露引起仔鼠海马神经元细胞凋亡异常及其调控基因的变化可能是其导致仔鼠学习记忆障碍的重要机制之一。综上所述,一定剂量母源性BDE-209暴露可破坏仔鼠海马组织结构,导致仔鼠学习记忆能力障碍,提示BDE-209具有神经发育毒性。对其机制的初步探讨发现,可能与母源性BDE-209暴露后所致海马神经发育相关蛋白表达下降,氧化损伤,神经细胞过度凋亡有关。更多还原

【Abstract】 Polybrominated diphenylethers (PBDEs) are a widely used class of organic brominated flame retardants. Over the previous 20 years, concentrations of PBDEs have been increasing in sediment, fish, bile, human milk, serum and adipose tissue due to the persistence and bioaccumulation of these materials. Especially in human tissue, the concentrations of PBDEs were found to be 8.61—46.05 ng/g lipid; mean, 19.33 ng/g lipid in blood; 6.2- 419 ng/g lipid in milk; 17-9630 ng/g lipid in adipose tissue. The most widely used congener of the PBDEs is BDE-209, and the world wide use of this congener was 56100 metric tones for the year 2001, and the levels tend to increase over time .It is also interesting to note the fact that levels of BDE-209 markedly exceed the levels of all other congeners ,especially since BDE-209 is the only PBDE still in production.The toxic effects of PBDEs are currently a rising public concern. Their structural similarity to PCBs has caused attention to focus on the potential effects to the developing nervous system. The most important risk of PBDEs exposure is developmental neurotoxicity. Mouse receiving PBDEs during the brain spurt, manifested spontaneous deranged behavior, learning and memory defects, and dysfunction in the cholinergic system in adult, all of which worsen with age, calls for further studies of the neurotoxicity of PBDEs.Hippocampus play a central role in the process of learning and memory. Therefore, the present study explores the effects of different concentrations of the matreal BDE-209 on oxidative stress, signaling proteins, and apoptosis in hippocampus of offsping rats, and examines the correlation between the presence of ROS and the levels of signaling proteins and apoptosis. The results provide useful information for further study of the mechanism of BDE-209 induced neurotoxicity.Part I EFFECT OF MATERNAL BDE-209 EXPOSURE ON SPACIAL LEARNING AND THE MICROSTRUCTURE INHIPPOCAMPUS OF OFFSPRING RATS[Objective]To evaluate the effect of the maternal BDE-209 on the offspring rats’s learning andmemory ability and the change of the microstructure in hippocampus.[Material and Methods]1 .Fifty female rats were be divided in 5 groups freedly. The experimental group weregiven BDE-209 in doses of 100(A)、300(B)、600(C)、1200(D) mg/ kg·d by oralgavage when they are in gestational and lactational. The control group wasadministered only with the same capacity of Peanut oil at the same time.2.Twenty male offspring rats of each group will be exzamed by the method of 100 ofthe offspring rats will be examined of their learning and memory ability by the method of Morris water maze when they are 28 days old.3. Hippocampus were obtained from five offspring rats of each group after Morriswater maze. The change of microstructure in hippocampus were observe by lightmicroscope after HE staining.[Results]1.Offspring rats of the experimental group have lower learning and memory abilitycompared with the control group .There is singnifcant difference in learning andmemory ability between the group C、D and the group E (P<0.05, <0.01),but there isnot in the group A and B.2. Obvious histomorphology changs were found in group C and D in hippocampus ofthe offspring rats.[Conclusions]1. High dose maternal BDE-209 exposure will diminish the offsprings’ ability oflearning and memory.2.High dose maternal BDE-209 exposure can affect the the development of nerve celland damage the microstructure of hippocampus.Part II EFFECT OF MATERNAL BDE-209 EXPOSURE ON THE CAMKⅡCONTENT AND THE EXPRESSION OF GAP-43、BDNF IN HIPPOCAMPUS OF OFFSPING RATS[Objective]The previous work confirmed that neurotypic and gliotypic proteins can serve as sensitive indicators of time- and region-specific effects of chemicals on the developing nervous system. In the present study ,several biochemical indices were choosed to characterize the effects of BDE-209 on neonatal brain development. We hypothesized that the effects of PBDE on critical developmental processes would be reflected by changes in the biochemical substrates underlying them. The levels of several proteins involved in neuronal survival, growth, and synaptogenesis were examined. There are signaling proteins that are highly enriched in the nervous system and regulate neuronal processes which peak during the brain growth spurt. In this study CaMKⅡ、GAP-43 and BDNF were measured to observe the effect of the maternal BDE-209[Material and Methods]1. Hippocampus were obtained from ten offspring rats of each group after Morris water maze.2. The levels of CaMK II in hippocampus were examined using sandwich ELISA procedures.3. The expression of GAP-43 and BDNF in the hippocampus were examined by means of immunohistochemistry.[Results]1.The CaMKⅡactivity in hippocampus decreased in different level. The group C、D had significant difference from control group(P=0.031, P=0.005); The group A and B had no significant difference from control group(P=0.526, P=0.284); In the experiment groups, the group A had significant difference from the group D (P=0.025) .But there is no significant difference of CaMKⅡactivity between the group B、C and the group D(P=0.068, P=0.474).2.There is singnifcant difference of the expression of GAP-43 in hippocampus between the group C、D and the group E (P=0.013, P=0.000). There were no significant differences between the group A、B and the group E (P=0.177, P=0.093). In the experiment groups, the group A、B had significant difference from the group D (P=0.011, P=0.025) .But there is no significant difference between the group C and the group D (P=0.157).3.There is singnifcant difference of the expression of BDNF in hippocampus between the experiment group (group B、C、D) and the control group (P=0.033, P=0.005, P=0.001);There was no significant differences between the group A and the control group(P=0.066). In the experiment groups, the group A、B、C had no significant difference from the group D (P=0.052, P=0.103, P=0.409) .[Conclusions]The present result show that biochemical assessment of proteins involved in normal brain development may be useful biomarkers for developmental neurotoxicity. All three of these proteins are known as biochemical substrates for cellular processes (including neurite outgrowth and synaptogenesis) which support the formation of proper connectivity in the nervous system. The relationship between chemical-induced changes in these biochemical substrates of growth and plasticity during the brain growth spurt and possible morphological and functional consequences remains to be determined.Part III EEFFECT OF MATERNAL BDE-209 EXPOSURE ON THE SOD ACTIVITY AND THE MDA CONTENT IN HIPPOCAMPUS OF OFFSPRING RATS[Objective]Our initial studies quantified the maternal BDE-209 exposure can damage the ability of learning and memory of the offsprings rats. The toxic effect is not very clear, many studies suggest that xenobiotics can facilitate the active oxygen derived free radicals formation, which make many tissue systems in oxidative stress situation. The developmental nervous system is especially susceptible to it. In This study, lipid peroxidation of BDE-209 was observed in the hippocampus of offspring rats after the maternal BDE-209 exposure.[Material and Methods]1. Hippocampus were obtained from ten offspring rats of each group after Morris water maze.2. The SOD activity is determined by a hydroxylamine assay which was developed from a xanthine oxidase assay using chemical colorimetry. After reaction, the absorbance at 560 nm was monitored using a spectrophotometer.3. The colorimetric determination of MDA is based on the reaction of one molecule of the reactive aldehyde with two molecules of thiobarbituric acid at low pH (2-3) and 95℃for 45 min. The resultant pink color was extracted by n-butanol, and the absorbance at 532 nm was determined with a spectrophotometer.[Results]1. The SOD activity in hippocampus of the experiment groups of the offsprins rats decreased in different level. The group C、D had significant difference from control group(P=0.016, P= 0.000); There were no significant differences between the group A、B and the group E(P=0.180, P=0.068). In the experiment groups, the group A、B had significant difference from the group D (P=0.003, P=0.013) .But there is no significant difference between the group C and the group D (P=0.059).2. The MDA content in hippocampus of the experiment groups of the offsprins rats increased in different level, the groups C、D had significant difference from the control group(P=0.000, P=0.000); There were no significant difference between the group A、B and the group E (P=0.407, P=0.081). In the experiment groups, the group A、B had significant difference from the group D (P=0.001, P=0.014) .But there is no significant difference between the group C and the group D (P=0.451).[Conclusions]The studies suggest that BDE-209 can facilitate the ROS formation, which makemany tissue systems in oxidative stress situation. Lipid peroxidatic produce MDAincreased obviously, and activity of antioxidant enzyme SOD decreased; whichindicated that maternal BDE-209 exposure can make lipid peroxidation in centralnervous system.Part IV EFFECT OF MATERNAL BDE-209 EXPOSURE ON THE EXPRESSION OF BCL-2 AND BAX GENE IN HIPPOCAMPUS OF OFFSPRING RATS[Objective]Apoptosis is a cellular autonomy death model controlled by genes, which is completely different from cellular necrosis in morphology. Apoptosis contributes to the selective elimination of cells in physiologic and pathologic situations. Some studies have suggested that apoptosis involves the participation, at different levels, of ROS like hydrogen peroxide, superoxide anion, and singlet oxygen. The aim of this study is to evaluate the effect of maternal BDE-209 on expression of Bcl-2 and Bax gene in hippocampus of offspring rats .[Material and Methods]1. Hippocampus were obtained from five offspring rats of each group after Morris water maze.2. The expression of Bcl -2, Bax mRNA in hippocampus of the offspring rats were examined by RT-PCR. [Results]1.The results of PCR indicated that the positive expression of Bcl-2 in hippocampusof the experiment groups of the offsprins rats decreased in different level. Thegroups C、D had significant difference from the group E (P=0.011, P=0.005); Therewere no significant differences between the group A, B and the group E (P=0.459,P=0.174). There is significant difference between the group A and the group D(P=0.025).2. The positive expression of Bax in hippocampus of the experiment groups of theoffsprins rats decreased in different level. The groups C、D had significant differencefrom control group(P=0.032, P=0.002); There were no significant differencesbetween the group A、B and the group E(P=0.525, P=0.167). There is significantdifference between the group A and the group D (P=0.010).[Conclusions]Maternal BDE-209 exposure can decrease the positive expression of Bcl-2, increasethe positive expression of Bax in the offspring rat’s hippocampus, indicating thatapoptosis was involved in the neurotoxic mechanism of BDE-209 .As a regulatinggene, Bcl-2 and Bax may participate in hippocampus neuron apoptosis induced byBDE-209.SUMMARY1.High dose maternal BDE-209 exposure will diminish the offsprings’ learning andmemory abilityand can affect the development of nerve cell and chang themicrostructure.2.Biochemical assessment of proteins involved in normal brain development may beuseful biomarkers for developmental neurotoxicity. CaMKⅡ、GAP-43 and BDNF areknown biochemical substrates for cellular processes (including neurite outgrowth and synaptogenesis) which support the formation of proper connectivity in the nervous system. The relationship between hemical-induced changes in these biochemical substrates of growth and plasticity during the brain growth spurt and possible morphological and functional consequences remains to be determined.3. Maternal BDE-209 can facilitate the ROS formation, which make many tissue systems in oxidative stress situation. Lipid peroxidatic produce MDA increased obviously, and activity of antioxidant enzyme SOD decreased; which indicated that the maternal BDE-209 can make lipid peroxidation in central nervous system. 4.Matemal BDE-209 exposure can decrease the positive expression of Bcl-2, increase the positive expression of Bax in the offspring rat’s hippocampus, indicating that apoptosis was involved in the neurotoxic mechanism of BDE-209 .As a regulating gene, Bcl-2 and Bax may participate in hippocampus neuron apoptosis induced by BDE-209.更多还原