Aroclor1254对雄性大鼠的生殖毒性效应

目的探讨Aroclor1254对成年雄性大鼠的生殖毒性效应。方法将90 d的成年雄性SD大鼠(体质量250~300 g)随机分为溶剂对照组和Aroclor1254低、中、高剂量(1、3、5 mg/kg)组,每组8只。采用腹腔注射法连续给药,制备SD大鼠生精障碍模型,溶剂对照组给予等体积玉米油,给药30 d后麻醉处死大鼠,记录各组大鼠体质量、睾丸和附睾质量,计算睾丸和附睾器官系数并检测各组大鼠给药后精子数。采用苏木素-伊红(HE)染色观察睾丸组织病理学变化。结果与溶剂对照组比较,Aroclor1254低、中、高剂量组大鼠的体质量、睾丸和附睾质量、睾丸和附睾器官系数、精子计数均随剂量升高而降低,以高剂量组降低最多〔体质量(g):278.32±5.60比301.05±4.35,睾丸质量(g):1.39±0.08比1.66±0.04,附睾质量(g):0.35±0.07比0.54±0.05,睾丸器官系数:(5.00±0.25)%比(5.51±0.10)%,附睾器官系数:(1.20±0.24)%比(1.80±0.22)%,精子计数(×10^(6)个):11.50±1.06比19.50±2.92,均P<0.05〕。Aroclor1254处理组大鼠生精小管结构破坏、排列紊乱、两生精小管间质细胞减少,且随剂量升高症状加重。结论Aroclor1254暴露可能通过破坏血睾屏障的完整性损伤大鼠生殖功能。

Aroclor1254预先染毒增强苯并[a]芘对Hep G2细胞DNA的损伤

目的 :探讨Hep G2细胞经Aroclor1254预处理后对苯并[a]芘诱发的DNA损伤的影响。 方法 :运用单细胞凝胶电泳技术检测了HepG2细胞经Aroclor1254(23、46、92和184μmol/L)单独染毒24h和将其预处理24h后再用苯并[a]芘染毒1h对DNA损伤的影响。 结果 :苯并[a]芘诱发的DNA损伤随着Aroclor1254预处理的浓度增大而升高 ,呈明显的剂量效应关系。当Aroclor1254预处理的浓度分别为46、92和184μmol/L时 ,苯并[a]芘诱发的DNA损伤与苯并[a]芘单独作用相比分别升高了8 %、16 %和160 %。184μmol/L的Aroclor1254预处理后 ,苯并[a]芘诱发的DNA损伤与苯并[a]芘单独作用相比有极显著性差异(P<0.01)。 结论 :Aroclor1254可显著地增强苯并[a]芘在HepG2细胞中诱导的DNA损伤 ,这种损伤的增强可能和Aro clor1254对Hep G2细胞CYP1A1的诱导有关。

Aroclor1254对大鼠甲状腺结构及功能的影响

为探讨低浓度多氯联苯(polychlorinated biphenyls,PCBs)商业混合物Aroclor1254对大鼠甲状腺结构及功能的影响,本文将12只雄性Wistar大鼠随机分为对照组和PCBs暴露组(Aroclor1254组),对照组腹腔注射Aroclor1254的溶剂玉米油,暴露组以2000μg·kg-1·d-1的剂量行腹腔注射Aroclor1254,每周注射5d,连续注射13周.采用HE染色、免疫组化及电镜技术观察PCBs对大鼠甲状腺组织结构的影响,酶联免疫吸附试验(ELISA)检测血清TSH、Free-T3、Free-T4水平,逆转录聚合酶链反应(RT-PCR)检测甲状腺球蛋白(Tg)及钠碘转运体(NIS)mRNA表达水平.研究结果发现,与对照组比较,暴露组大鼠甲状腺组织内单核巨噬细胞(ED-1+细胞)浸润增多,甲状腺微观结构受损,血清TSH水平显著升高,甲状腺组织TgmRNA及NISmRNA表达显著下调.研究结果表明,低浓度PCBs长期暴露可导致大鼠甲状腺结构破坏及功能损伤.

Aroclor1254对斑马鱼胚胎发育、肝脏组织结构及其卵黄蛋白原基因的影响

[目的]使用脊椎动物模型斑马鱼评价Aroclor1254对斑马鱼胚胎发育、肝脏组织结构以及卵黄蛋白原(vtg)基因表达的影响,为Aroclor1254的毒性效应研究提供基础数据,以期选择Aroclor1254污染的敏感指标,进行早期污染监测和预警。[方法]将斑马鱼及其胚胎暴露在不同浓度的Aroclor1254溶液中,运用斑马鱼胚胎发育技术和组织病理观察法以及实时定量反转录聚合酶链反应(RT-PCR)检测Aroclor1254对斑马鱼胚胎发育的影响、形态学的改变和卵黄蛋白原(vtg)基因的表达。[结果]斑马鱼胚胎试验显示,3.3、6.5、10.0mg/L Aroclor1254等均可诱导肝变性、肝脏发育不全,其中3.3mg/L Aroclor1254诱导斑马鱼卵黄部分变性,6.5、10.0mg/L Aroclor1254诱导斑马鱼卵黄大部分或者全部变性。肝脏组织病理观察发现,2.0、10.0、50.0μg/L Aroclor1254肝细胞肿大,胞质疏松,空泡明显增加,细胞质中可见脂沉积。vtg mRNA的表达在Aroclor1254暴露的斑马鱼个体中产生了显著的改变,雌鱼中表达普遍呈抑制趋势,其中以2.0μg/L抑制现象最明显,而在雄鱼中该剂量组vtg表达量被显著诱导。[结论]研究表明Aroclor1254对斑马鱼及其胚胎具有毒性效应,肝脏是产生毒性效应的重要靶器官。

槲皮素对Aroclor1254诱导的孕鼠肝细胞CYP450表达的影响

采用胶原酶二步灌流法获取怀孕大鼠的原代肝细胞，以Aroclor1254诱导肝细胞损伤，用不同剂量的槲皮素分别处理损伤的肝细胞24～72h，RT—PCR及Western—blot法检测肝细胞中细胞色素酶P450（CYP450）的表达。结果显示，槲皮素处理损伤的肝细胞后，肝细胞CYPIAl、CYP281及CYP2E1的表达随槲皮素浓度的增加和处理时间的延长而呈先升高后降低的趋势。10mg／LAroclor1254是诱导体外培养的原代肝细胞损伤的最适质量浓度，10μmol／L槲皮素是对损伤的怀孕大鼠肝细胞的最佳保护浓度。结果表明，槲皮素对损伤的怀孕大鼠肝细胞具有保护作用。

Effects of Quercetin on Cytochrome P450 expressions of Aroclor1254-induced Hepatocytes in pregnant Rats

In order to investigate the protective effects of quercetin on Aroclor 1254-injuried hepatocytes in pregnant rats. The primary cultured rat hepatocytes were isolated by two-step collagenase digestion method,and Aroclor 1254 was used to make the injuried hepatocytes model. These hepatocytes were treated with gradient quercetin for 24 ~ 72 h,respectively,and the expressions of CYP1A1,CYP 2B1 and CYP 2E1 were determined by RT-PCR and Western blot. The expressions of CYP1A1,CYP 2B1 and CYP 2E1 in injuried rat hepatocytes increased gradually at first,then decreased with the treatment of the gradient quercetin for different time respectively. 10 μg / mL Aroclor 1254 was the optimal concentration to induce the primary cultured rat hepatocytes injury in vitro,CYP450 expression of the injuried hepatocyte model was optimal by 10 μmol / L quercetin induction. These show that quercetin has protective effects to the injuried hepatocyte model in the pregnant rats.

植物组织培养基中多氯联苯的抽提方法

利用恒温磁力搅拌器以及震荡方法对琼脂培养基(MS)样品中持久性有机污染物Aroclor1254提取方法进行了研究。将等量样品培养基中分别加入等体积的正己烷,利用恒温磁力搅拌器进行搅拌处理和振荡器的震荡处理,分别在15、30、45、60、75、90 min,6个时间点检测正己烷中Aroclor1254的含量。发现通过磁力搅拌器进行处理的样品在15 min后的提取浓度基本稳定,与通过震荡器震荡处理的样品90 min时的提取浓度基本持平,无显著性差异,搅拌所用的时间明显短于震荡的时间。

多氯联苯(Aroclor 1254)对小鼠生殖毒理的组织病理学研究

以小鼠为实验动物模型,采用腹腔注射染毒法研究二噁英类环境激素多氯联苯(Aroclor 1254)对小鼠的生殖毒性,并用组织病理学方法研究毒性机理。内脏的组织病理学现察结果表明,不同发育阶段接触多氯联苯的小鼠,在心脏、肝脏、脾脏、肺脏和肾脏均出现有组织病理学变化。心脏主要表现心肌纤维颗粒变性,间质毛细血管扩张、充血。肝脏主要表现肝细胞胞浆及胞核的病理变化,中央静脉、小叶间静脉扩张、充血。脾脏主要表现红髓轻度充血,轻度含铁血黄素沉着,巨核细胞及淋巴细胞增多,出现炎性细胞;脾小体数量增加,脾小体周围淋巴细胞增生、部分细胞核染色质减少,甚至成空泡状。肺脏主要表现胞壁毛细血管扩张,局部充血、出血;动脉扩张充血;肺泡隔增厚。肾小管尤其是近曲小管上皮细胞肿胀,上皮细胞颗粒变性,有的胞浆崩解使管腔狭窄,甚至堵塞:部分肾小球肿胀、充血,胞核染色质淡染,有的成空泡样:肾小囊狭窄;间质毛细血管扩张、充血、甚至出血:远曲小管胞浆溶解,残存一些散在的细胞核,个别细胞核染色质减少,甚至成为空泡状。组织病理学变化的程度及表现的种类存在剂量-效应变化规律;并存在个体发育时期与效应的变化规律。

多氯联苯(Aroclor 1254)对小鼠生殖系统毒理的组织病理学研究

以小鼠为试验动物,采用腹腔注射染毒法研究二噁英类环境激素多氯联苯(Aroclor1254)对小鼠的生殖毒性,并用组织病理学方法研究毒性机理。组织病理学变化的程度及表现的种类存在剂量-效应变化规律,并存在个体发育时期与效应的变化规律,较高剂量时变化比较明显。

Impact of poly chlorinated biphenyl (Aroclor 1254) and vitamin C on antioxidant system of rat ventral prostate

Aim: To evaluate the effect of polychlorinated biphenyls (PCB) and vitamin C on ventral prostatic antioxidant system in adult male rats. Methods: A group of 20 adult male rats were administered ip Aroclor 1254 in corn oil at a dose of 2 mg·kg-1·day-1 for 30 days. Ten control rats were administered only the vehicle. After 30 days the treated rats were divided at random into 2 sub-groups of 10 animals each. One sub-group received vitamin C at a dose of 500 mg·kg-1·day-1 for 10 days. The other group was maintained as Aroclor 1254 control. Twenty-four hours after the last treatment the rats were killed by decapitation. Ventral prostatic homogenate was prepared and used for the estimation of enzymatic antioxidants, including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) and hydrogen peroxide (H2O2), lipid peroxidation (LPO) and prostatic acid phosphatase. The serum levels of total T3, total T4, TSH, testosterone and estradiol were also assayed. Results: The body weight and ventral prostatic weight were reduced in PCB treated rats. The activities of SOD, CAT, GST and acid phosphatase were decreased while the levels of H2O2 and lipid peroxidation were increased in the ventral prostate of PCB treated rats. Administration of vitamin C restored these parameters. Serum levels of thyroid hormones, estradiol and testosterone were decreased in PCB treated animals. Administration of vitamin C restored the thyroid hormone levels. Conclusion: PCB induces oxidative stress and decreases the antioxidant enzymes in the ventral prostate of adult male rats; the effects could be reversed by the administration of vitamin C.

Assessing Adverse Effects of Aroclor 1254 on Perinatally Exposed Rat Offspring

To assess the neurotoxic effects and redoxresponses of Aroclor 1254 （A1254） on perinatallyexposed rat offspring, A1254 was administered bygavage from gestational day （GD） 6 to postnatal day（PND） 21. Neurobehavioral development,antioxidant enzyme activities, lipid peroxidation（LPO）, nitric oxide （NO）, and NO synthase （NOS）levels were analyzed in the offspring.Neurobehavioral development analysis revealeddelayed appearance of the righting reflex, negativegeotaxis, and cliff drop test responses in A1254exposed group. Developmental A1254 exposurealso caused oxidative stress in the brain of PND 22offspring via reductions in the activity of SOD andGSH-Px, and by promoting a rise in the levels of NOand NOS.

孕哺期接触多氯联苯对大鼠子代学习记忆及海马神经元的影响

目的 探讨孕哺期接触多氯联苯对仔鼠学习记忆的影响及生理机制.方法 成年Wistar大鼠受孕后用不同浓度的aroclor1254染毒,仔鼠出生1个月后进行水迷宫实验,分离海马细胞测定细胞内游离钙离子浓度,透射电镜观察海马神经元的超微结构.结果 各组仔鼠经过4d训练后潜伏期与第1天相比均明显缩短（P＜0.05）,但在同一天中染毒组与对照组的潜伏期差异无统计学意义;空间探索实验中,各剂量组仔鼠第一次穿越平台时间与对照组相比均延长,其中中、高剂量组与对照组差异明显[（11.74±6.56）s、（20.83±8.38）s,（5.23±1.16）s;均P＜0.05）],各剂量组在第四象限的停留时间与对照相比均明显减少[分别是（40.14±7.14）s,（33.76±5.58）s,（32.45±6.00）s,（30.63±5.10）s;P＜0.05];穿越平台次数随着染毒剂量增加而减少[分别为（4.14±1.21）次,（3.00±1.32）次,（2.65±1.13）次,（2.42±1.31）次;P＜0.05）],中高剂量组差异具有统计学意义（P＜0.05）,中高剂量组与对照组和低剂量组相比在目标象限停留时间明显减少[（40.14±7.14）s,（33.76±5.58）s,（32.45±6.00）s,（30.63±5.10）s）;P＜0.05].染毒组细胞内游离钙离子浓度明显增高[分别为（121.16±12.23） nM,（141.27±24.66） nM,（163.32±29.75） nM,（261.46±27.79） nM],中高剂量组差异具有统计学意义（P＜0.05）.高剂量组海马神经元结构被破坏,表现为线粒体肿胀,脊排列紊乱,核膜崩解,脱髓鞘改变.结论 Aroclor 1254孕哺期染毒能引起子代大鼠学习记忆能力降低和超微结构的改变,这种作用可能与细胞内钙离子稳态失衡有关.

多氯联苯促进毛白杨不定根分化的效应

多氯联苯是一种典型的持久性有机污染物。研究表明多氯联苯具有毒物兴奋效应,但其影响植物生长发育的机制尚不清楚。以毛白杨(Populous tomentosa)组培苗为材料,探讨3mg·L^-1Aroclor1254对不定根分化、植物激素水平、与生长素相关的P009g125900、P006g142600和P002g2227003因表达、与细胞分裂素相关的P005g2489和P005g2376基因表达的影响。结果显示,Aroclor1254可促进毛白杨组培苗不定根分化,缩短不定根初根时间与分化率达100%的时间,提高不定根数目:在不定根诱导期,用Aroclor1254单独诱导,IAA/(ZR+dhZR)比值与阳性对照无显著差异,P006g142600、P002g222700、P009g125900、P005g2489和P005g2376基因表达变化趋势与IBA单独诱导下各基因表达变化趋势一致。为验证Aroclor1254是否具有生长素效应,以玉米(Zea mays)和转生长素报告基因DR5::GUS的拟南芥(Arabidopsis thaliana)为材料,观察Aroclor1254对胚芽鞘生长及DR5::GUS基因表达的影响。结果显示,一定浓度的Aroclor1254对胚芽鞘的生长无显著影响,但可诱导生长素报告基因表达。以上结果表明,多氯联苯类化合物Aroclor1254虽不属于植物生长调节剂,但具有毒物兴奋效应,在一定浓度下具有类似生长素的生物学活性。

多氯联苯增强苯并(a)芘致HepG2细胞DNA的损伤作用

目的研究多氯联苯1254对苯并(a)芘致HepG2细胞DNA损伤的影响。方法设11.5、23.0和46.0μmol/L多氯联苯1254剂量组,苯并(a)芘50μmol/L剂量组,10 m l/L二甲基亚砜为溶剂对照。用不同浓度多氯联苯1254预处理HepG2细胞,24 h后染毒,通过单细胞凝胶电泳和高效液相-电化学技术,检测细胞中的DNA链断裂和8-羟基脱氧鸟嘌呤核苷酸(8-OHdG)。结果50μmol/L苯并(a)芘诱导HepG2细胞中DNA O liver尾矩(OTM)值为1.66±0.21,8-OHdG含量为(23.31±6.02)8-OHdG/106dG,溶剂对照组OTM值为0.79±0.15,8-OHdG含量为(12.31±3.24)8-OHdG/106dG,两组比较差异均有统计学意义;11.5、23.0和46.0μmol/L单独处理组OTM值分别为0.88±0.20、1.01±0.15和1.10±0.16,8-OHdG含量分别为(19.57±7.57)、(22.80±9.16)和(31.74±9.25)8-OHdG/106dG,46.0μmol/L组与溶剂对照组比较,8-OHdG含量显著增加,差异有统计学意义;经11.5、23.0和46.0μmol/L的多氯联苯1254预处理,苯并(a)芘诱导的OTM值分别为2.14±0.22、2.43±0.32和2.71±0.31,8-OHdG含量分别为(32.50±3.81)、(49.23±16.66)和(60.36±18.04)8-OHdG/106dG,与苯并(a)芘单独作用组比较均显著增加,差异有统计学意义。结论多氯联苯1254能使苯并(a)芘诱导的HepG2细胞DNA损伤作用显著增强,表明多氯联苯1254对苯并(a)芘的遗传毒性作用具有一定的协同效应。

雌激素受体α在Aroclor 1254促进GC-1细胞增殖中的作用

目的研究Aroclor 1254对生精细胞增殖的影响及其可能机制,探讨雌激素受体α(estrogen receptorα,ERα)在此过程中的作用。方法体外培养GC-1细胞,用不同浓度的Aroclor 1254(0、0.05、0.5和5 mg/L)处理。采用MTT法检测细胞存活率;采用蛋白免疫印迹法(Western blot)检测ERα及其下游蛋白的表达;采用ERα特异性阻断剂MPP抑制ERα表达,进而研究ERα在Aroclor 1254影响GC-1细胞增殖中的作用。结果Aroclor 1254可以明显促进GC-1细胞增殖及cyclin D1的表达;Aroclor 1254染毒可使GC-1细胞中ERα及磷酸化细胞外调节蛋白激酶1/2(phospho-extracellular regulated protein kinases 1/2,p-ERK1/2)的表达水平明显升高;MPP阻断ERα表达后,Aroclor 1254对p-ERK1/2表达及细胞增殖的促进作用被部分逆转。结论Aroclor 1254可促进生精细胞增殖,其机制可能是通过上调ERα的表达继而诱导ERK1/2磷酸化,并最终促进生精细胞增殖。

Toxic effects of polychlorinated biphenyls （Aroclor 1254） on human sperm motility

Polychlorinated biphenyls （PCBs） are common environmental contaminants that represent a considerable risk to reproductive toxicity in exposed human populations. Although some experimental studies have suggested an association between the levels of PCBs and semen quality, the direct effects of PCBs on human sperm parameters remain largely unexplored. To this aim, a short-term in vitro incubation experiment that better imitated the putative exposure of sperm to Aroclor 1254 （a commercial PCB mixture） in male reproduction tissue was conducted. Human sperm were incubated with various concentrations （0, 1, 5, or 25 mg ｜^-1） of Aroclor 1254 for different amounts of time （3 and 6 h） in vitro. Sperm motility parameters were analyzed with computer-assisted sperm analysis （CASA）. The proportion of sperm with high mitochondrial membrane potential （ΔΨm） and the levels of intracellular reactive oxygen species （ROS） were detected to explore the probable cause of sperm impairment. Human sperm exposed to continuous Aroclor 1254 exhibited： （i） reduced sperm motility and kinematic parameters, （ii） a proportion of sperm with high ΔΨm that decreased in a dose-dependent manner （P 〈 0.05）, and （iii） increased levels of ROS compared with controls （P 〈 0.05）. In conclusion, Aroclor 1254 can decrease sperm motility, which may culminate in increased ROS and general mitochondrial dysfunction, thus affecting the fertilization potential of sperm. Our findings suggest a broader understanding of the effect of Aroclor 1254 on human soerm.

Determination of Aroclor 1254 in Water Samples Using Polystyrene-Divinylbenzene Solid-Phase Extraction and Gas Chromatography

A method was developed for the determination of Aroclor 1254 in water samples using polystyrene-divinylbenzene(PS-DVB)solid-phase extraction(SPE)and gas chromatography(GC).The PS-DVB sorbent demonstrated good recoveries of Aroclor 1254 when sulfuric acid(1:1,v:v)was added to the samples.Sample quantification was performed using gas chroma-tography with a parallel column and dual electron capture detector.Factors in extraction method procedures were optimized,including sample pH,elution solvent,eluting volume and breakthrough volume.With the 1000 ml sample acidified to pH 1.0,a 6.0 ml n-hexane/ethyl acetate(1:1,v:v)elution solvent,and gas chromatographic determination,the recoveries of Aroclor 1254 in spiked water samples ranged from 90.6 to 104%.Across testing days,repeatability ranged from 4.7 to 7.6%.The method detection limit was 0.053μg/L.PS-DVB exhibited a broader pH stability range,satisfactory recoveries,and good repeatability for Aroclor 1254 extraction.The results indicate that these methods can be used to analyze trace amounts of Aroclor 1254,and represent a new analytical approach for determining polychlorinated biphenyls in water samples.