PFOS致大鼠肝毒性及其作用机制研究

通过全氟辛烷磺酸(perfluomoctane sultanate,PFOS)大鼠灌胃染毒实验评价PFOS对肝功能的影响,探讨PFOS肝毒性反应的潜在机制与可能途径。将Sprague Dawley (SD)雄性大鼠随机分为3组,分别以0 mg·kg~(-1)、5 mg·kg~(-1)和10 mg·kg~(-1)PFOS灌胃染毒28 d。以HE和油红染色法观察大鼠肝脏形态改变。ELISA法测定各组谷丙转氨酶(alanine aminotransferase,ALT)、谷草转氨酶(aspartate transaminase,AST)、碱性磷酸酶(alkaline phosphatase,ALP)含量变化。化学比色法测定肝匀浆脂代谢水平和氧化产物含量。RT-PCR法检测肝脏内氧化应激以及脂代谢相关基因表达水平。结果表明,PFOS暴露大鼠体重显著降低而肝脏系数显著增加(P0.05),与对照组相比PFOS组血清肝功能酶均出现随PFOS浓度增加而升高(P0.05)。同时大鼠肝脏谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-px)和丙二醛(malondialdehyde,MDA)水平在高剂量组显著升高(P0.05),超氧化物歧化酶(superoxide dismutase,SOD)含量先显著升高(P0.05)后显著降低(P0.05)。且肝脏中脂代谢水平也随PFOS浓度的增加而出现显著改变(P0.05)。PFOS组基因表达均较对照组显著上升(P0.05)。以上结果说明PFOS具有明显的肝毒性作用,可影响肝脂代谢水平,这可能与PFOS引起的氧化应激所导致的损伤有关。     

内质网应激介导的凋亡在PBDE-47致大鼠海马损伤中的作用

为了明确内质网应激(endoplasmic reticulum stress,ERS)介导的凋亡在2,2’,4,4’-四溴联苯醚(2,2’,4,4’-tetrabromodiphenylether,PBDE-47)致大鼠神经毒性中的作用,在脑发育的突增期(出生第10天),分别用0 mg·kg~(-1)、1 mg·kg~(-1)、5 mg·kg~(-1)和10mg·kg~(-1)PBDE-47进行单次灌胃染毒,并从出生第8天开始每天给予150 mg·kg~(-1)ERS抑制剂4-苯基丁酸(phenylbutyric acid,PBA),持续3周。仔鼠出生第8周末,从对照组、10 mg·kg~(-1)PBDE-47处理组、150 mg·kg~(-1)PBA处理组和150 mg·kg~(-1)PBA+10mg·kg~(-1)PBDE处理组中随机选取8只大鼠进行水迷宫实验。然后将所有动物断头处死,分离大鼠海马组织,观察其海马组织形态学改变、测定ERS标志分子(GRP78、IRE1和CHOP)和凋亡相关蛋白Cyt c的表达水平。结果显示,10 mg·kg~(-1)PBDE-47处理可导致雌性大鼠海马CA4区细胞排列紊乱、锥形神经细胞数量减少甚至消失,尼氏小体数量减少,大鼠逃避潜伏期延长(P0.05)。5和10 mg·kg~(-1)PBDE-47处理可显著上调ERS相关蛋白IRE1和CHOP的表达水平(P0.05),并明显增强海马组织凋亡相关蛋白Cyt c的表达。PBA干预可明显降低PBDE-47诱导的IRE1和CHOP以及Cyt c蛋白的表达水平,提示PBDE-47可通过ERS介导凋亡,导致大鼠海马组织损伤,从而影响大鼠学习记忆功能。     

丙烯腈诱导的氧化应激对大鼠肝脏内质网应激信号通路的影响

为探讨丙烯腈(acrylonitrile,ACN)诱导的大鼠肝脏氧化损伤对内质网应激(endoplasmic reticulum stress,ERS)信号通路的影响,我们将50只SPF级成年雄性SD大鼠按体重随机分为5组,每组10只。各组分别以12.5、25.0、50.0 mg·kg~(-1)ACN灌胃染毒,N-乙酰半胱氨酸(N-acetylcysteine,NAC)干预组先用300.0 mg·kg~(-1)NAC灌胃30 min后再灌50.0 mg·kg~(-1)ACN,对照组以0.5 mL·(100 g)~(-1)的玉米油灌胃,1次·天~(-1),6天·周~(-1),共计13周。染毒结束后,检测肝脏组织氧化还原酶活力及丙二醛(malondialdehyde,MDA)含量,GRP78、CHOP及caspase-12 mRNA及蛋白表达水平。结果显示:低、中ACN组大鼠肝脏GSH含量显著低于对照组(P0.05);低ACN组大鼠肝脏GSH-Px活力、SOD活力及MDA含量均显著高于对照组(P0.05);中、高ACN组大鼠肝脏CAT活力明显低于对照组(P0.05)。NAC干预后可逆转ACN诱导的大鼠肝脏GSH含量、MDA含量及SOD活力的变化。RT-PCR结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12 mRNA表达水平与对照组比较均升高(P0.05)。NAC干预后,CHOP、caspase-12 mRNA表达水平与高ACN组比较均降低(P0.05)。Western Blot结果显示,高ACN组大鼠肝脏GRP78、CHOP、caspase-12蛋白表达水平与对照组比较均升高(P0.05),NAC干预后可逆转以上作用。结果表明,ACN慢性染毒对大鼠肝脏的氧化损伤可激活ERS信号通路,NAC可减轻氧化损伤的程度而阻断ERS信号通路,这可能是ACN产生肝脏毒性的机制之一。     

三(1,3-二氯-2-丙基)磷酸酯诱发肝脏损害及病理改变研究

本研究观测有机磷酯阻燃剂(OPFRs)污染是否可以诱发肝脏损害,考察其发生及发展程度,并探讨其发生机理,为有机磷阻燃剂污染的防治和相关疾病的有效治疗提供基础数据和科学依据。实验以大鼠为动物模型,将60只SPF级SD雄性大鼠分为5组,每组12只,选取典型的氯代有机磷阻燃剂三(1,3-二氯-2-丙基)磷酸酯(TDCPP)对大鼠进行染毒,空白对照组不做任何处理,溶剂对照组以相同体积的橄榄油灌胃,染毒组以不同剂量的TDCPP进行灌胃(125 mg·kg~(-1)·d~(-1)、250 mg·kg~(-1)·d~(-1)和500 mg·kg~(-1)·d~(-1)),每周测量体重,于第4周和第8周取血检测肝功及其他生化指标,在第8周每组抽取3只大鼠取肝脏组织做HE染色,并用透射电镜观察分析肝组织病理学改变。TDCPP对大鼠染毒8周后,结果表明:(1)体重指标在灌胃1周后开始发生差异,TDCPP处理组大鼠的体重有下降的趋势,染毒组与空白对照组和溶剂对照组相比较,差异显著(*P0.05,**P0.01),其中高剂量灌胃组的体重下降最为明显(**P0.01);(2)血清肝功指标表现出显著变化,血清谷丙转氨酶、谷草转氨酶、胆固醇和甘油三脂水平在第8周呈现明显下降趋势,染毒组与空白对照组和溶剂对照组比较,差异明显(*P0.05,**P0.01);(3) TDCPP暴露组生理生化指标变化明显,血清乙酰胆碱酯酶活性显著降低,MDA含量显著升高,SOD活力显著性降低,造成氧化损伤,与空白对照组和溶剂对照组比较,差异显著(*P0.05,**P0.01);(4)病理切片结果显示染毒组与对照组比较,细胞坏死现象明显,且高剂量组坏死更为严重。研究结果显示:TDCPP可引起大鼠体重明显下降,大鼠肝脏细胞损伤、合成功能下降,造成肝脏代谢功能紊乱,造成较为严重的肝损伤。     

丙烯腈诱导的氧化应激对大鼠睾丸NF-κB信号通路的影响

为探索丙烯腈(acrylonitrile,ACN)诱导的氧化应激对大鼠睾丸NF-κB信号通路的影响,将50只SPF级健康SD雄性大鼠按体重随机分为12.5、25、50 mg·kg~(-1)ACN染毒组,50 mg·kg~(-1)ACN+300 mg·kg~(-1)N-乙酰半胱氨酸(N-acetylcysteine,NAC)干预组(NAC干预组),对照组(给予等体积玉米油),每组10只,灌胃,1次/天,6天/周,共90 d。可见光分光光度法检测睾丸组织中超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、还原型谷胱甘肽/氧化型谷胱甘肽比值(glutathione/oxidized glutathione,GSH/GSSG)、丙二醛(malondialdehyde,MDA)。免疫荧光染色法检测睾丸核因子-κB(nuclear factorκB,NF-κB)激活及核转移。Western Blot检测睾丸p65、IκB蛋白表达。结果显示,低、高剂量染毒组大鼠睾丸GSH/GSSG比值、GSH-Px酶活性与对照组比较降低(P0.05)。中、高剂量染毒组大鼠睾丸MDA含量与对照组比较升高(P0.05)。NAC干预组大鼠睾丸MDA含量与高ACN组比较降低(P0.05);NAC干预组大鼠睾丸GSH/GSSG比值与高ACN组比较升高(P0.05);免疫荧光结果显示,高ACN组大鼠睾丸NF-κB被激活,并转移入细胞核。NAC干预组与高ACN组比较p65蛋白表达及核转移显著减少。Western Blot结果显示,高剂量染毒组大鼠睾丸p65蛋白表达与对照组比较升高(P0.05),IκB蛋白表达与对照组比较降低(P0.05);NAC干预组大鼠睾丸p65蛋白表达与高ACN组比较降低,IκB蛋白表达与高ACN组比较升高,差异有统计学意义(P0.05)。结果表明丙烯腈引起的氧化应激激活了大鼠睾丸生殖细胞NF-κB信号通路。     

全氟辛烷磺酸对哮喘小鼠炎症反应的影响

探讨全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)暴露对哮喘小鼠Th1/Th2炎症反应的影响。选择36只雄性C57BL/6J小鼠,随机分为6组:对照组、卵清蛋白(ovalbumin,OVA)单独致敏组、PFOS染毒组(0.1、1、5、10 mg·kg~(-1)·d~(-1) PFOS+OVA致敏),每组6只。染毒和诱发哮喘后第26天收集肺泡灌洗液(BALF)进行有核细胞总数和嗜酸性粒细胞计数;用Luminex技术测定BALF中细胞因子白细胞介素-5(interleukin-5,IL-5)、白细胞介素-4(interleukin-4,IL-4)和γ干扰素(interferon-γ,IFN-γ)水平;肺组织切片染色观察其病理变化。随PFOS暴露浓度的增加,嗜酸粒细胞总数呈上升趋势(P0.05),IL-5/IFN-γ比值增加(P0.05);其中10 mg·kg~(-1)·d-1PFOS+OVA组BALF中的白细胞总数显著高于OVA单独组(P0.05),IL-4水平及IL-4/IFN-γ比值显著高于OVA单独组(P0.05),且与单独OVA组相比小鼠气道粘膜及粘膜下层厚度更厚,炎症细胞浸润更明显,PAS染色阳性的气道上皮细胞明显更高。PFOS能加重哮喘小鼠肺部的炎症反应并诱导Th2型细胞因子的表达。     

丙烯腈暴露对大鼠脑组织损伤及iNOS/p38 MAPK信号通路关键蛋白表达的影响

通过探究iNOS/p38 MAPK信号通路在丙烯腈(acrylonitrile,ACN)诱导脑组织损伤中的作用,为进一步研究ACN的神经毒性作用提供依据。选取50只SPF级健康成年雄性SD大鼠,随机分为5组,每组10只。适应性饲养一周后,以12.5、25.0、50.0 mg·kg~(-1)ACN对大鼠进行灌胃染毒,对照组给予玉米油,另设NAC组(300.0 mg·kg~(-1)NAC+50.0 mg·kg~(-1)ACN),1次·天~(-1),6天·周~(-1),共染毒13周。次日称重并处死大鼠,测定大鼠脑组织NO含量、总NOS水平及iNOS、p-p38和p38蛋白表达水平。结果显示,ACN各剂量组大鼠脑组织脏器系数与对照组比较均显著降低(P0.05),高剂量组大鼠脑脏器系数与NAC组比较降低(P0.05)。高剂量组NO含量和总NOS水平显著高于对照组,与NAC组比较,高剂量组NO含量降低(P0.05),总NOS水平升高(P0.05)。Western blot结果显示,ACN高剂量组大鼠脑组织iNOS、p-p38蛋白表达水平和p-p38/p38比值显著高于对照组和NAC组(P0.05)。ACN可激活iNOS/p38MAPK信号通路,这可能是ACN致大鼠脑组织损伤的机制之一。     

长期饲喂钬对鲤鱼非特异性免疫酶活性的影响

以鲤鱼为研究对象,进行为期60 d的饲喂试验,研究了硝酸钬对其非特异性免疫的影响。结果表明:与对照组相比,在实验剂量范围内,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)在肝脏中呈先升高后降低的趋势,SOD、GSH-Px酶活性在20 mg·kg~(-1)时,升高显著(P0.05),三者在65 mg·kg~(-1)时都被显著抑制(P0.05);在肾中都被诱导,在65 mg·kg~(-1)升高显著(P0.05)。肝肾中丙二醛(MDA)含量都变化不显著(P0.05)。抗超氧阴离子自由基、抑制羟自由基能力和单胺氧化酶(MAO)活性都降低,且在65 mg·kg~(-1)时降低显著(P0.05或P0.01)。因此,在饲料中添加稀土元素钬20、42、65 mg·kg~(-1),能够影响非特异性免疫力,且鲤鱼肝组织比肾脏反应更敏感。     

孕鼠PFOS暴露对糖皮质激素水平及胎鼠生长发育的影响

为探究孕期全氟辛烷磺酸(PFOS)暴露与母源糖皮质激素(GC)水平、胎鼠生长发育之间的关系,将孕期为12 d(GD12)的24只SD雌性大鼠,随机分为4组给予不同剂量的PFOS(0,5,10,20 mg·kg-1),连续灌胃7 d,在GD19时对孕鼠和胎鼠的体重、胎鼠肝脏系数和肝脏生化指标、孕鼠血清的生化指标和GC水平、胎盘11β-羟基类固醇脱氢酶2(11β-HSD2)的酶学活性和胰岛素样生长因子-1(IGF-1)的mRNA表达水平分别进行检测。结果表明,与对照组相比:PFOS 20 mg·kg-1组,母鼠体重、胎鼠体重和体长显著下降(P0.001);PFOS 20 mg·kg-1组,胎鼠肝脏脏器系数低于对照组(P0.001);PFOS 10 mg·kg-1组,胎鼠肝脏中的酶活性(ALT、AST和ALP等)显著升高(P0.001);PFOS 20 mg·kg-1组,孕鼠血清GC水平升高(P0.05);胎盘IGF-1的mRNA表达水平随PFOS剂量升高而降低;胎盘11β-HSD2的活性随PFOS剂量升高而降低。研究表明,孕期暴露PFOS可以导致胎鼠肝脏毒性,降低胎盘11β-HSD2氧化活性导致GC浓度升高,进而影响胎鼠的生长发育。     

芹菜素对丙烯腈引起大鼠精子脂质过氧化和DNA损伤的影响

分析芹菜素(apigenin,AP)对丙烯腈(acrylonitrile,ACN)引起的大鼠精子脂质过氧化和DNA损伤的影响,并探讨其可能的机制。将50只SPF级SD成年雄性大鼠随机分为阴性对照组(玉米油)、ACN组(50 mg·kg~(-1)ACN)、低AP组(50 mg·kg~(-1)ACN+234 mg·kg~(-1)AP)、高AP组(50 mg·kg~(-1)ACN+468 mg·kg~(-1)AP)、N-乙酰半胱氨酸(N-acetylcysteine,NAC)组(50 mg·kg~(-1)ACN+300mg·kg~(-1)NAC),以5 m L·(kg bw)~(-1)灌胃染毒,1次·d~(-1),6 d·周~(-1),连续13周。检测大鼠精子活性氧(ROS)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性以及精子DNA损伤情况。结果发现,ACN组、低AP组、高AP组、NAC组精子ROS、MDA含量显著升高,SOD活力显著降低,精子尾部DNA含量百分比、尾长、尾距、Olive尾距均显著增高于对照组(均P0.05);而低AP组、高AP组、NAC组精子ROS、MDA含量、SOD活性和精子DNA损伤情况与ACN组相比差异均无统计学意义(P0.05)。提示ACN可引起大鼠精子脂质过氧化和DNA损伤,而AP、NAC对其无干预作用。     

全氟辛烷磺酸(PFOS)对三角帆蚌肝胰腺的氧化性损伤

PFOS是典型的持久性有机污染物,迁移能力强,具有较高的生物可利用性和蓄积能力,且具有广泛的生物毒性。为探究PFOS对淡水底栖生物的毒性作用机制,以三角帆蚌为研究对象,进行了不同剂量(0.1、1.0、5.0 mg·L-1)的PFOS胁迫和净水恢复实验,期间对受试生物肝胰腺中的谷胱甘肽(GSH)含量、谷胱甘肽-S转移酶(GST)活性、超氧化物歧化酶(SOD)活性,以及谷丙转氨酶(ALT)和谷草转氨酶(AST)的活性进行了连续测定。结果发现,低浓度胁迫(0.1 mg·L-1)对各项指标均有不同程度的诱导作用,且持续时间较长;而在中高浓度PFOS胁迫下,则呈现出明显的诱导向抑制过渡的时间效应。GSH含量和GST活性具有较高的相关性(P0.05)。恢复实验中,所测指标普遍未恢复到对照组水平,说明P FOS胁迫损伤的恢复需要更长的时间。研究表明,PFOS对三角帆蚌肝胰腺的氧化胁迫显著,并能快速地激活肝胰腺细胞的解毒代谢;但长期的PFOS胁迫则会造成肝胰腺细胞的实质性损伤。     

Effect of calcium and magnesium on copper,cadmium, and some essential elements of Indian major carps Labeo rohita (Hamilton) and Catla catla (Hamilton) treated with copper and cadmium

The effect of calcium and magnesium either singly or in combination on accumulation of cadmium and copper in Labeo rohita (rohu) and Catla catla (catla) was investigated in this study under laboratory conditions. The investigation showed that copper accumulation in rohu exposed to 0.25 mg L^?1 of copper for 14 days reduced from 31.0 ± 0.4 mg kg^?1 at no calcium/magnesium treatment to 3.5 ± 0.2 and 2.2 ± 0.1 mg kg^?1, respectively, at 75 mg L^?1 calcium or magnesium treatment. The copper level in catla exposed to 0.20 mg L^?1 of copper for 14 days reduced from 5.7 ± 0.1 mg kg^?1 at no calcium/magnesium treatment to 3.4 ± 0.2 and 3.3 ± 0.1 mg kg^?1, respectively, at 300 mg L^?1 calcium or magnesium treatment. The cadmium accumulation in rohu exposed to 0.20 mg L^?1 of cadmium for 14 days reduced from 1.7 ± 0.1 mg kg^?1 at no magnesium treatment to 1.4 ± 0.1 mg kg^?1 at 120 mg L^?1 magnesium treatment. The cadmium accumulation in catla exposed to 0.20 mg L^?1 of cadmium for 14 days reduced from 0.8 ± 0.2 mg kg^?1 at no magnesium treatment to 0.6 ± 0.2 mg kg^?1 at 80 mg L^?1 magnesium treatment. Copper and cadmium treatments also reduced some essential microelements of rohu and catla. Both the fishes restored these elements at different levels of calcium and magnesium.     

伊维菌素对雄性吉富罗非鱼生理生化指标的影响

为探讨抗寄生虫药物伊维菌素(IVM)对鱼类的毒性效应,以雄性吉富罗非鱼(Oreochromis niloticus)为实验对象,设定了A(空白对照)、B(乙醇对照)、C(0.1 mg·kg~(-1))、D(0.5 mg·kg~(-1))、E(1 mg·kg~(-1))5个实验组,研究IVM对吉富罗非鱼肝脏和血液生理生化的影响。研究发现:正常生理状态下吉富罗非鱼肝脏中的丙二醛(MDA)含量较低,IVM作用后除最高剂量E组中MDA含量在4 h、16 h和24 h时极显著高于对照组外,其余各组均未受到显著影响。较低注射剂量C组中超氧化物歧化酶(SOD)活性均得到了诱导,且均显著高于对照组,较高注射剂量组中除E组在第4 h、16 h和24 h SOD活性显著高于对照组外,其余均未发现有显著变化。肝脏中谷草转氨酶(AST)和谷丙转氨酶(ALT)在IVM作用下均发生了一定的变化,尤其是E组均显著低于对照组。与肝脏中的相反,血液中的AST则随剂量的升高而呈现增加的趋势,在某些时间点与对照组相比显著升高,而血液中ALT除C、D组个别时间点外其余的均未有显著变化。B、C、D、E 4组肝脏中的碱性磷酸酶(ALP)相对A组均发生了显著下降,但C、D、E组与B组除个别时间点外均未有显著差异,因此肝脏中的ALP变化可能是无水乙醇作用的结果,而非IVM。血液中ALP则均未有显著变化。研究表明高剂量的IVM对吉富罗非鱼的肝脏造成了一定影响,因此在实际使用过程中应选择合适的给药方式以及合理的给药剂量。     

口服纳米银对大鼠的生物有效性及其体内分布的研究

由于独特的抗菌特性，纳米银(AgNP)在诸多领域得到广泛应用，但是其生物有效性、动物组织分布及排出尚不清楚。将聚乙烯吡咯烷酮包被的AgNP溶液按照10 mg kg^-1给雌性SD大鼠灌胃，采用ICP-MS检测SD大鼠组织、粪便及尿液中总银浓度。实验结果表明，AgNP通过小肠吸收后，可以通过血液循环快速分布在肝、肾、脾、肺、脑等靶器官。灌胃后1 h，大鼠各组织中总银浓度达到最大值(肝、肾、脾、肺、脑中银浓度分别为0.29 ± 0.13 mg kg^-1、0.23 ± 0.04 mg kg^-1、0.17 ± 0.05 mg kg^-1、0.11 ± 0.01 mg kg^-1、0.06 ±0.02 mg kg^-1)，之后银浓度随时间降低直至和对照组无显著性差异。在灌胃途径下，AgNP对SD大鼠的有效性为8.5%，且73%的AgNP是通过粪便的途径排出体外。     

Arsenic in freshwater ecosystems of the Bengal delta: status,sources and seasonal variability

The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L^?1 (mean 31 ± 2 µg L^?1) and sediment 1.3–37.3 mg kg^?1 (mean 10.3 ± 0.4 mg kg^?1), than those from the unaffected area: water 1–8 µg L^?1 (mean 4 ± 0 µg L^?1) and sediment 1.4–5.3 mg kg^?1 (mean 3.0 ± 0.1 mg kg^?1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region.     

PFOS对多齿围沙蚕CYPs、GST基因转录及酶活性的毒性效应

多毛类沙蚕已经广泛应用于海洋环境污染的生物监测,但其对新型持久性有机污染物全氟辛烷磺酰基化合物PFOS的毒理学研究尚无报道。本研究以潮间带优势种多齿围沙蚕(Perinereis nuntia)为研究对象,以细胞色素P450(CYP)、谷胱甘肽硫转移酶(GST)的基因和酶作为联合指标,研究了在PFOS亚致死浓度(4、8、16 mg·L-1)暴露第1、4、7、14天及净水恢复5 d后多齿围沙蚕CYP431A1、CYP424A1基因转录水平和EROD酶活性、GST omega基因转录水平和GST酶活性的响应情况。结果表明,PFOS暴露对EROD的抑制具有明显的时间-效应关系;CYP2系成员CYP431A1基因转录水平对PFOS的响应具有良好的剂量-效应关系并在胁迫第14天表现出最高的可诱导性;CYP4系基因CYP424A1的转录在4、8 mg·L-1处理组中与PFOS暴露时间正相关。II相解毒系统成员GST酶活和GST omega基因的响应均表现出随着PFOS胁迫时间的延长先下降,后上升的规律;多齿围沙蚕在高强度PFOS胁迫下仍可加速新陈代谢,表现出对PFOS的耐受性;净水恢复阶段,各指标都有向对照组水平恢复的趋势。总之,基因和蛋白的响应表明CYPs和GST在多齿围沙蚕PFOS新陈代谢中发挥重要作用,这些基因和酶具有作为生物标志物监测海洋潮间带PFOS污染效应的潜力。     

Lead-induced alterations in protein-deficient rat liver–role of zinc

This study was designed to determine the protective effects of zinc (Zn) using liver marker enzymes in the serum and liver along with hepatic elemental profile in lead (Pb)-treated protein-deficient (PD) Sprague–Dawley male rats. Zn in the form of zinc sulfate at a dose of 227?mg?L^?1 in drinking water was administrated to control, PD as well as Pb-treated PD rats for 8 weeks. Pb treatment was given orally as lead acetate at a dose level of 100?mg?kg^?1 body weight to control and PD rats. The effects of different treatments were studied on the activities of enzymes that included alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum. The status of different elements (Cl, K, Mn, Fe, Cu, Zn, Se, Rb, Pb) in liver was also studied. Rats given PD diet and Pb showed significant inhibition in serum ALP activity associated with significant elevation in both AST and ALT activities. Serum ALP activity showed a significant inhibition week 1 until week 8 in Pb-treated PD rats. In contrast, serum AST activity was elevated both at 3 and 8 weeks while serum ALT activity was elevated at 8 weeks in Pb-treated PD rats. Pb treatment to PD rats elevated hepatic ALP, AST and ALT activities but depressed hepatic AST. Zn supplementation to Pb-treated PD rats restored the altered enzyme activities. The levels of K, Fe, Cu, Zn, Se and Rb were altered in protein deficiency. Furthermore, treatment with Pb to these animals depressed the Cu levels. Zn treatment to Pb-treated PD animals tended to restore the levels of altered elements. Hence, the present study clearly suggests that Zn plays an important role in regulating the liver marker enzymes and essential elements under conditions of Pb toxicity and protein deficiency.     

Lead and copper in the sclerotium of the mushroom Pleurotus tuber-regium (Osu): assessment of contribution to dietary intake in southeastern Nigeria

The concentrations of lead and copper in sclerotium of the mushroom Pleurotus tuber-regium widely consumed in Southeastern Nigeria were determined. The specimens purchased from different markets were mineralized with H₂SO₄ and H₂O₂ and analyzed using flame atomic absorption spectrophotometer. The concentrations of Pb ranged from 0.2?±?0.1?mg?kg^?1 to 0.8?±?0.5?mg?kg^?1 with approximately 91% of the results being below 1?mg?kg^?1. The concentrations of Cu ranged from 0.5?±?0.2?mg?kg^?1 to 1.2?±?0.6?mg?kg^?1 with 78% of the results below 1?mg?kg^?1. The results were compared with the literature and levels set by regulatory authorities, with the conclusion that the consumption of sclerotium does not pose a toxicological risk. The low Pb content of the studied products would contribute to only about 1% of the provisional tolerable weekly intake of Pb. The Cu contents would contribute to nutritional intake of the metal in the general population. It is recommended that the outer layers of the sclerotia be properly scrapped before use to reduce metal contamination from exogenous sources.     

Determination of metals in printed wiring boards of waste mobile phones

Metal contents of waste mobile phones represent a major environmental risk, especially considering the adoption of inappropriate management options in developing countries including open burning and disposal into surface water bodies. In this study the metal contents of mobile phone printed wiring board (PWB) samples were assessed. Sixty-two waste mobile phones of 15 brands were collected, dismantled, and their PWB samples were analyzed for Cu, Pb, Ag and Cd. The metal concentrations in the samples varied widely between and within brands. Among these metals, Cu and Pb were found to be at very high concentrations. The range (mean?±?SD) of Cu and Pb concentrations were 94.1–532?g?kg^?1 (250?±?92.3?g?kg^?1) and 7.0–46.2?g?kg^?1 (20.1?±?8.4?g?kg^?1), respectively. All Cu and Pb concentrations exceeded toxicity threshold limit concentration (TTLC) regulatory limits used in characterizing wastes as hazardous in the state of California, USA. The mean Cu and Pb concentrations exceeded the corresponding TTLC limits by factors of 100 and 20, respectively. The Ag and Cd concentrations were in the range 59.4–759?mg?kg^?1 (mean 227?±?104?mg?kg^?1) and ND – 15.6?mg?kg^?1 (2.1?±?3.3?mg?kg^?1), respectively.     

The potential of Berkheya coddii for phytoextraction of nickel,platinum, and palladium contaminated sites

The study involved assessing the potential of the native plant species (Berkheya coddii) for the phytoextraction of nickel, palladium, and platinum contaminated sites. Plant and soil samples were randomly collected from Barberton area, near Agnes mine, Mpumalanga Province, South Africa. Samples were analysed for total nickel, palladium, and platinum concentrations together with other elements found in the soil and in the plants' roots, and leaves. Soil versus leaves and soil versus roots uptake of these metals by the plant were compared. The mean concentration of nickel in the leaves/canopy was found to be 13,980?±?10,780?mg?kg^?1?dry mass, in the roots it was 2046?±?789?mg?kg^?1 dry mass, and in the soil it was 1040?±?686?mg?kg^?1?dry mass. This resulted in a mean concentration ratio in the leaves to soil of 13.44. The platinum mean concentration in the leaves was 0.22?±?0.15?mg?kg^?1?dry mass, in the roots it was 0.14?±?0.04?mg?kg^?1?dry mass, and in the soil it was 0.04?±?0.03?mg?kg^?1?dry mass. This resulted in a mean concentration ratio in the leaves to soil of 5.5. Palladium was found to have a mean soil concentration of 0.07?±?0.045?mg?kg^?1?dry mass. The mean concentrations in the roots and in the leaves were 0.18?±?0.07 dry mass and 0.71?±?0.52?mg?kg^?1?dry mass, respectively. This gave a mean concentration ratio in the leaves to soil of 10.1 for palladium. Other elements that were found to have a mean concentration ratio in the leaves to soil of around 2.5 or above are sodium, potassium, magnesium, calcium, and sulfur. Berkheya coddii was found to be most efficient in accumulating nickel, palladium, and platinum from the soil. The results for the first time revealed that the plant may have the potential to uptake platinum and palladium; both metals are in the same group of the periodic table as nickel.