孕期双酚A染毒对子代大鼠海马中诱导型一氧化氮合酶表达及活性的影响  

Effects of bisphenol A exposure during pregnancy on expression and activity of inducible nitric oxide synthase in hippocampus of rat offspring at different developmental stages

作　　者：梁嘉显 郭沛森 经楚煖 徐靖雅 刘娣 于海洋[1] LIANG Jiaxian;GUO Pei-sen;JING Chu-xuan;XU Jing-ya;LIU Di;YU Hai-yang(School of Public Health,Shenyang Medical College,Shenyang,Liaoning 110034,China)

机构地区：[1]沈阳医学院公共卫生学院,辽宁沈阳110034

出　　处：《环境与职业医学》2020年第4期327-333,共7页Journal of Environmental and Occupational Medicine

基　　金：国家自然科学基金项目(81803283);辽宁省博士科研启动基金指导计划(20170520041);辽宁省大学生创新创业训练计划(201810164013);沈阳医学院大学生科研课题(20189015)。

摘　　要：[背景]现有研究表明双酚A(BPA)具有一定的神经毒性。一氧化氮(NO)是神经系统的重要逆行信使,其含量改变在神经毒性机制中发挥一定作用。当外源性化学物作用于机体时,诱导型一氧化氮合酶(iNOS)表达与活性变化对于NO的生成具有一定影响。[目的]探讨孕期BPA染毒对各发育阶段子代大鼠海马中iNOS表达及活性的影响。[方法]将60只SPF级健康SD孕鼠随机分为对照组和0.05、0.5、5、50 mg·kg^-1·d^-1的BPA染毒组,每组12只。于妊娠期第5天(GD5)-GD19以灌胃的方式进行染毒,以玉米油为溶剂配制相应浓度的BPA试剂,对照组母鼠灌胃玉米油。于GD20每组各处死6只孕鼠,剥离胎盘,取胎鼠脑组织,分离海马;剩余6只孕鼠继续饲养,仔鼠于出生后第21天(PND21)断乳,分别于PND21和PND56时,每组取6只仔鼠,经乙醚麻醉后处死,取仔鼠的海马组织。计算GD20、PND21、PND56这3个发育阶段仔鼠脑组织脏器系数,采用试剂盒检测海马组织中的NO含量、iNOS活性,采用实时定量PCR法测定各组iNOSmRNA水平,通过Western blotting检测iNOS的蛋白表达。[结果]NO检测结果显示,GD20各BPA染毒组仔鼠海马组织中NO含量均低于对照组(均P <0.05);而PND21和PND56的各BPA染毒组仔鼠(除PND21的0.05 mg·kg^-1组外)海马组织中NO含量均高于对照组,但PND56的0.5、5、50 mg·kg^-1BPA组仔鼠海马中NO含量低于0.05 mg·kg^-1组(均P <0.05)。iNOS mRNA表达结果显示,各发育阶段的BPA组仔鼠海马中iNOS mRNA含量均高于对照组(均P <0.05);其中GD20的50 mg·kg^-1 BPA组仔鼠海马中iNOS mRNA含量低于0.5 mg·kg^-1组(P <0.05);PND21的0.5、5、50 mg·kg^-1 BPA组仔鼠海马中iNOS mRNA含量均低于0.05 mg·kg^-1 BPA组,5、50 mg·kg^-1组仔鼠海马中iNOS mRNA含量也低于0.5 mg·kg^-1 BPA组(均P <0.05);PND56的5 mg·kg^-1 BPA组仔鼠海马中iNOS mRNA含量高于0.05、0.5 mg·kg^-1组,而50 mg·kg^-1组的iNOS mRNA含量低于5 mg·kg^-1组(均P <0.05)。iNOS蛋白[Background] Available studies have shown that bisphenol A(BPA) could induce neurotoxicity. Nitric oxide(NO) is an important retrograde messenger in the nervous system, and the alternations of its level play an important role in the mechanism underlying neurotoxicity. When exogenous chemicals are applied to the body, changes in the expression and activity of inducible nitric oxide synthase(iNOS) may have an impact on the production of NO.[Objective] This experiment investigates the effects of BPA exposure during pregnancy on the expression and activity of iNOS in the hippocampus of rat offspring at different developmental stages. [Methods] Sixty SPF-grade healthy SD pregnant rats were randomly divided into control group and 0.05, 0.5, 5, and 50 mg·kg^-1·d^-1 BPA exposure groups, with 12 rats in each group. The pregnant rats in the exposure groups were exposed to BPA(dissolved in corn oil) via oral gavage daily from gestational day(GD) 5 to GD19, and the rats in the control group were fed with corn oil. Six pregnant rats were sacrificed in each group on GD20, the placenta was harvested and the hippocampus was separated from brain tissues. The remaining six pregnant rats of each group were fed continuously, and the infant rats were weaned on postnatal day(PND) 21. Six rat offspring of each group were sacrificed on PND21 and PND56 respectively after ether anesthesia, and the hippocampus was also taken. The organ coefficients of brain tissues of rat offspring at different developmental stages(GD20, PND21, and PND56) were calculated. The levels of NO and the activity of iNOS in the hippocampus were detected using biochemical kits. The expression levels of iNOS m RNA and protein in the hippocampus was detected by real-time quantitative polymerase chain reaction and Western Blotting respectively. [Results] The hippocampal NO levels of GD20 rat offspring in the BPA exposure groups were lower than that in the control group(Ps < 0.05);the hippocampal NO levels of PND21 and PND56 rat offspring in the BPA exposure groups(e

关 键 词：双酚A 孕期染毒 海马 一氧化氮 诱导型一氧化氮合酶 

分 类 号：R11[医药卫生—公共卫生与预防医学]