锌、金属硫蛋白、超氧化物岐化酶对镉中毒拮抗作用的比较

本研究用CdCl_2制备小鼠镉中毒模型,使发生明显的脂质过氧化损伤,锌、金属硫蛋白和超氧化物岐化酶分别预处理后,可降低中毒鼠死亡率,肝、肾组织中丙二醛含量明显降低,金属硫蛋白含量明显升高,肝组织中锌/铜比例升高。提示锌、金属硫蛋白和超氧化物岐化酶能拮抗镉引起的致死作用和脂质过氧化作用。     

锌和硒联合拮抗砷对小鼠的致微核作用

目的探讨锌和硒联合对砷致小鼠骨髓细胞微核变化的影响。方法采用小鼠骨髓微核试验。结果与对照组相比,染砷同时染硒,硒可明显地拮抗砷诱发小鼠微核变化的作用,且呈剂量反应关系;染砷同时染锌,锌可明显地拮抗砷诱发小鼠微核的作用,且呈剂量-效应关系。染砷同时染锌和硒,锌和硒可更明显地拮抗砷诱发小鼠微核的作用,且呈剂量-效应关系。结论锌和硒对砷致小鼠微核变化具有明显拮抗作用,为进一步研究及现场使用锌和硒防治砷中毒提供科学依据。     

维生素E和维生素C对大豆磷脂脂质体的抗氧化作用

利用分光光度法，研究了不同含量维生素Ｅ或维生素Ｃ对大豆磷脂脂质体的抗氧化保护作用及维生素Ｃ的存在和温度的变化对维生素Ｅ抗氧化作用的影响。结果表明，适量维生素Ｅ可明显抑制磷脂脂质体的氧化，含量越高，抑制作用越强；大量维生素Ｃ虽可起到抗氧化作用，但少量维生素Ｃ在铁离子的存在下却可起到促氧化作用；维生素Ｃ的存在对维生素Ｅ的抗氧化作用具有明显的协同作用；温度的升高有利于磷脂脂质的氧化。     

氟对大鼠脑组织蛋白激酶A的影响及硒、锌制剂的拮抗作用

本室以往研究表明 ,氟 (Ｆ)可诱导脑神经细胞凋亡。细胞凋亡涉及到极其复杂的信号转导过程 ,各种促凋亡因素往往需要通过细胞内第二信号系统 ,最终将凋亡信号传递至凋亡的最终共同通道 ,即改变细胞某些基因表达从而导致细胞凋亡的发生[1] 。环磷腺苷(ｃＡＭＰ)———蛋白激酶Ａ(ＰＫＡ)途径是细胞内一条重要的信号转导通路 ,在大多数情况下 ,该途径中ｃＡＭＰ是通过ＰＫＡ催化底物蛋白质磷酸化启动一系列级联反应的 ,故ＰＫＡ催化效应蛋白质磷酸化是产生下游效应的核心[2 ] 。ＰＫＡ在神经系统中作用广泛 ,其作用的底物有电压门控和配体门控…     

某地大气细颗粒物对大鼠肺损害与维生素E的拮抗作用

目的应用气管滴注法建立细颗粒物(PM2.5)染尘实验动物模型,探讨细颗粒物对大鼠肺组织的氧化性损伤作用及维生素E在细颗粒物(PM2.5)致肺组织损伤中的拮抗作用。方法健康成年Wistar大鼠48只随机分为空白对照组、生理盐水对照组、低剂量染尘组(1.5 mg/kg·bw)、低剂量染尘干预组、中剂量染尘组(7.5 mg/kg·bw),中剂量染尘干预组、高剂量染尘组(37.5 mg/kg·bw)、高剂量染尘干预组。生理盐水对照组大鼠气管滴注生理盐水(1.5 ml/kg),各染尘组及干预组用各组设定浓度的细颗粒物生理盐水混悬液进行气管滴注,3组干预组初次染尘后即给予添加维生素E的饲料进行干预,添加量为500 mg/kg。每周染尘1次,共4次,于最后一次染尘后2 d内处死,测定肺泡灌洗液中乳酸脱氢酶(LDH),酸性磷酸酶(ACP),碱性磷酸酶(AKP),丙二醛(MDA)活力。结果空白对照组和生理盐水对照组各指标差异均无统计学意义(P>0.05),各剂量染毒组与生理盐水对照组相比差异均有统计学意义(P<0.05),且随着染尘剂量增加各指标活性水平升高,呈现剂量-效应关系。维生素E各干预组与同剂量染尘组比较各指标差异均有统计学意义(P<0.05),即干预组与同剂量染尘组指标水平比较明显降低。结论环境细颗粒物对大鼠肺组织可造成一定程度的氧化性损伤作用,维生素E对其造成的损伤具有一定的拮抗作用。     

铅对大鼠海马齿状回 LTP 及 PPF 的损伤和锌的拮抗作用

铅对大鼠海马齿状回ＬＴＰ及ＰＰＦ的损伤和锌的拮抗作用吴英赵艳梅阮迪云（中国科学技术大学生物系，合肥２３００２７）新生Ｗｉｓｔａｒ小鼠在发育过程中通过母鼠哺乳方式摄入微量铅或铅加锌．用在位电生理方法记录成年鼠海马齿状回颗粒细胞的兴奋性突触后电位（ＥＰＳ...     

维生素E和维生素C联合应用对慢性镉中毒小鼠黑质神经元的保护作用

目的探讨维生素E（Vit E）和维生素C（Vit C）联合用药对慢性镉中毒小鼠黑质神经元的保护作用。方法小鼠染镉同时给予大量Vit E和Vit C，通过光镜观察小鼠黑质神经元的细微结构，并用细胞形态计量方法对黑质区酪氨酸羟化酶（TH）阳性反应神经元进行定量分析。结果Vit E和Vit C加镉组小鼠中脑黑质区结构接近正常对照组，与镉中毒组比较有明显不同，黑质神经元胞核体密度、数密度等形态学参数与镉中毒组比较差异有统计学意义。结论抗氧化剂Vit E和Vit C对慢性镉中毒组小鼠黑质神经元有显著的保护作用。     

维生素E、C对砷抑制细胞间通讯的拮抗作用

砷是自然界中广泛存在的一种类金属元素,国际癌症研究机构于1979年将无机砷正式确认为人类致癌物,但砷致癌的机制仍不很清楚。研究表明砷可能是一种促癌物[1,2]。抑制细胞缝隙连接通讯(gapjunctional intercellular communication,GJIC)是促癌物的共同特征。有研究结果发现,亚砷酸可通过促进蛋白激酶C(protein kinase C,PKC)的异常活化而抑制细胞GJIC,从而发挥其促癌作用[3]。研究表明,亚砷酸在其代谢过程中,会产生大量的氧自由基,可导致细胞DNA损伤和断裂[4]。二甲胂酸可导致细胞异常增殖而起着促癌物的作用[5]。砷代谢过程中产生的…     

α-硫辛酸与维生素C和维生素E的抗氧化作用比较

维生素C和维生素E以及α-硫辛酸是三种重要的维生素类物质,必须由食物供给[1-3].20世纪初,维生素C防治坏血病成为光辉的一页;20世纪中叶,维生素E又成为防癌抗衰老的新秀;近年来发现α-硫辛酸也具有许多重要生理作用[4-8];但它们三者的共同特点是都具有很强的抗氧化活性.虽然它们的抗氧化途径各不相同,抗氧化效果也有很大差别,却都能有效清除体内自由基对细胞的毒性作用,从而起到保护细胞的作用.本研究是从它们提高细胞抗氧化能力和协助细胞从氧化损伤状态下恢复这两个方面来研究,旨在为进一步探讨三种物质的抗氧化机制奠定基础,也为一些需要长时间暴露在环境空气中进行的细胞实验积累有益资料,并为需要在高氧环境下进行的临床治疗研究提供参考数据.     

锌和硒对CCl4肝损害保护作用的实验研究

实验用ＳＤ大鼠。ＣＣｌ４经口染毒５００ｍｇ／ｋｇ。每周２次。连续染毒６周。染毒的同周分别给予锌（６ｍｇ／ｋｇ混入饲料中喂饲）。硒（３μｇ／ｍｌ饮用水供饮用）及ＶｉｔＥ（１０ｍｇ／ｋｇ腹腔注射，每周二次），共给１０周。于每隔两周处死一批动物，１０周实验的结果显示，ＣＣｌ４染毒后表现为ＳＧＰＴ活性、ＭＤＡ含量升高，ＧＳＨ、Ｐ４５０及ｂ５的含量下降，Ｚｎ、Ｓｅ和ＶｉｔＥ处理组其ＳＧＰＴ活性升高的幅度低于ＣＣｌ４组，上升的峰值也迟两周出现。停止染毒后，Ｚｎ，Ｓｅ组ＳＯＰＴ活性迅速下降，于第八周恢复对照组水平，并比ＶｉｔＥ组早两周达正常。各处理组ＭＤＡ含量值也表现为上升的幅度低，染毒停止后迅速恢复。Ｚｎ组ＧＳＨ第六周才有显著下降，第八周即恢复，Ｓｅ组则在整个观察期未见有显著的下降。各组染毒后细胞色素Ｐ４５０含量均下降。除Ｚｎ组于第八周达对照组水平外，其他组至第一周仍低于阴性组，细胞色素ｂ５含量Ｚｎ组、Ｓｅ组和ＶｉｔＥ组则于第四周开始下降，第八周恢复。组织病理学改变表现为ＶｉｔＥ、Ｚｎ、Ｓｅ组肝损害程度轻于ＣＣｌ４组。在抗纤维化上Ｓｅ和Ｚｎ优于ＶｉｔＥ。     

鱼腥草注射液中铅镉砷汞铜残留量的测定

目的建立测定鱼腥草注射液中铅镉砷汞铜残留量的方法。方法采用石墨炉原子吸收分光光度法测定铅、镐含量;火焰原子吸收分光光度法测定铜含量;氢化物发生-原子荧光法测定砷汞含量。结果铅、镐、砷、汞、铜的回收率分别为98．01％、90．17％、88．91％、86．68％、84．83％。结论该方法操作简便、快速,可用于鱼腥草注射液中铅镉砷汞铜残留量的测定。     

Breeding near a landfill may influence blood metals (Cd,Pb, Hg,Fe, Zn) and metalloids (Se,As) in white stork (Ciconia ciconia) nestlings

Cadmium, lead, mercury, selenium, iron, zinc and arsenic levels were measured in blood samples from 59 free-ranging white stork nestlings from colonies located in three different environmental conditions in Western Spain. The reference colony was situated in “Llanos de Cáceres y Sierra de Fuentes”, an Area of Special Interest for Bird Protection. A second colony was located close to (4.9 km) an urban landfill and a third one was close to both an intensive agricultural area and an urban landfill (1.5 km). Blood samples were diluted and elemental analysis was performed using inductively coupled plasma mass spectrometer. In all cases, the essential metals zinc and iron were found at the highest mean concentrations followed by lead > selenium > mercury > arsenic > cadmium. Regarding toxic metals, the highest concentrations were found for lead (ranging from 23.27 to 146.4 µg/L) although in all cases the concentrations were lower than those considered to cause subclinical effects. The metals levels detected in the chick’s blood were not related to the previously reported levels in the soil next to the colonies, which may indicate that landfills are the main source of metals in white stork nestlings. The present data showed that metal levels in white stork chicks may be influenced by the use of landfills as feeding areas by the parents. However, more studies on the metal content in the feed of white stork and the influence of the distance to the landfill are necessary to establish the causality of these findings.     

电感耦合等离子质谱法测定百部药材中砷、镉、汞、铅的含量

目的：建立电感耦合等离子质谱法（ICP-MS法）测定百部药材中砷、镉、汞、铅含量的方法。方法样品经微波消解后,以铟（In）、金（Au）为内标,采用ICP-MS同时测定上述4种元素。结果所测元素标准曲线的相关系数r＞0．9987,回收率在94．22％～97．50％之间,RSD均小于5％。结论该研究建立的方法具有较低检出限及高灵敏度,可用于百部药材的质量控制。研究结果表明环境对百部药材中砷、镉、汞、铅含量影响较大,可能导致其超出现有《中国药典》（2010年版）中限量标准。     

Voltammetric quality control of biologically active additives: determination of Zn,Cd, Pb,Cu, Fe,As, and Se

A new procedure for the voltammetric determination of toxic (As, Cd, Pb) and essential (Se, Cu, Zn, Fe) elements in various biologically active food additives (FAs) based on phytopreparations has been developed. Sample preparation includes the acid (HNO₃ + H₂O₂) or UV destruction of interfering substances followed by the reduction of As(V) and Se(VI) to the corresponding electroactive As(III) and Se (IV) forms. The elements Zn, Cd, Pb, and Cu are simultaneously determined using a mercury film electrode; As and Fe are determined sequentially, and Se is analyzed separately using a gold/graphite electrode and an appropriate supporting electrolyte. The content of elements in various analyzed FAs varied in a broad range of concentrations (mg/kg): Zn, 0.3–10000; Cd, 0.001–0.5; Pb, 0.001–0.5; Cu, 0.1–200; As, 0.01–1.0; Fe, 20–2000; and Se, 0.1–50. Metrological attestation performed with a large number of samples (above 400) showed a repeatability of 9%, a reproducibility of 13%, and an accuracy of 30%. The proposed analytical procedure is included into the Federal Register of Methods issued by the State Standard Pharmacological Committee of the Russian Federation, which includes methods admitted for use in the field of State Metrological Control and Supervision, and is recommended for use in laboratories of FA producing plants, state sanitary-epidemiological supervision offices, etc. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 11, pp. 50–53, November, 2005.     

Cytotoxicity and accumulation of Hg,Ag, Cd,Cu, Pb and Zn in human peripheral T and B lymphocytes and monocytes In Vitro

• 1.1. The cytotoxic effects of various heavy metals were assayed by trypan blue exclusion in vitro in human peripheral immune cells separated to high purity. T and B lymphocytes and monocytes were equally sensitive to metals. The individual metals could be ranked in the following decreasing order of cytotoxic potency, Hg ≈ Ag ≥ Cd ≈ Cu ≥ Pb ≈ Zn, based on exposure time and concentration needed to give a particular percentage of dead cells.
• 2.2. The cytotoxic effects became irreversible after about 13 hr of metal exposure.
• 3.3. Examination by scanning electron microscopy showed that the heavy metals caused serious destruction of the cell membranes.
• 4.4. Solubility and uptake of metals into the cells were studied and discussed in relation to the cytotoxic effects. It was concluded that metal binding to cell surfaces or precipitate formation could inhibit ordinary uptake, thereby affecting cytotoxicity. For Pb in monocytes this appeared to lead to uptake of non-toxic complexes, probably by phagocytosis.

     

Differential effect of N-acetylcysteine on excretion of the metals Hg,Cd, Pb and Au

Male Wistar rats were subacutely treated with sublethal doses of HgCl₂, CdCl₂, Pb(NO₃)₂, or Na-aurothiomalate. The metal preparations contained trace doses of radioactive nuclide. Based on the doses given and on the radioactivity excretion in urine and faeces the body burden was determined. After the metal treatment periods, some of the animals received N-acetylcysteine (up to 100 mg/kg daily, on 6 consecutive days, i.p.), and the effect of this potential chelator on metal excretion was monitored. The excretion of Hg (after dosing with HgCl₂) was not influenced by N-acetylcysteine. The elimination of Cd in urine (after dosing with CdCl₂) was increased by a factor of four. Also, the elimination of Pb [after dosing with Pb(NO₃)₂] was gradually increased (in faeces and urine) by increasing doses of N-acetylcysteine. After dosing with Na-aurothiomalate, the excretion of Au in urine was increased to about 30%. The data suggest some activity of N-acetylcysteine in facilitating excretion of Pb, Cd or Au, but not of Hg.This is an abridged report on the research conducted. The full material is available from the authors on request     

三种中成药中铅镉砷汞残留量测定方法研究

目的：建立三种中成药（京制咳嗽痰喘丸、活胃散、耳聋左慈丸）中铅、镉、砷、汞残留含量的测定方法。方法：采用微波消解样品。用石墨炉原予吸收法测定铅、镉含量，原予荧光光谱法测定砷、汞含量。结果：铅的回收率在107．4％～111．8％，镉的回收率在82．8％～97．5％，砷的回收率在89．0％～94．5％，汞的回收率在102．58-129．98％。结论：本方法操作简便、快速，且准确度争精密度高。     

Cd Resistant Cells show Cross Tolerance to Zn++ but not to Hg++

Abstract Orange RN (monosodium salt of l–phenylazo–2–naphthol–6–sulphonic acid) was administered to female pigs either by intraveneous injection or by stomach tube. After intravenous injection of Orange RN, 7.8 mg/kg, the following metabolites were indentified in 24–hour urines: Orange RN (31 %), l–(4–hydroxyphenylazo)–2–naphthol–6–sulphonic acid (3 %), p–aminophenol and o–aminophenol (34 % and 4 % of the theoretical yield, respectively). l–Amino–2–naphthol–6–sulphonic acid was present, but not determined. When the urine collection was extended to 72 hours the excretion of p–aminophenol accounted for the remainder of the phenylazo moiety. The excretion pattern for p–aminophenol suggests that Orange RN is partly excreted in the bile and thereafter undergoes azo reduction in the gut. After administration of Orange RN, 78 mg/kg, by stomach tube the following metabolites were identified in the urine: Total coloured metabolites (Orange RN and l–(4–hydroxyphenylazo)–2–naphthol–6–sulphonic acid) (0.4 % of the theoretical yield), p–aminophenol and o–aminophenol (52 % and 6 % of the theoretical yield, respectively) and aniline (0.3 % of the theoretical yield). 1–Amino–2–naphthol–6–sulphonic acid was present, but not determined.     

当归饮片及当归配方颗粒中铅镉砷汞残留量的测定

目的 建立测定当归饮片及当归配方颗粒中铅、镉、砷、汞残留量的方法.方法 采用聚四氟乙烯消化罐程序升温消解样品,以石墨炉原子吸收分光光度法测定铅、镉的含量;蒸气发生-原子荧光光谱法测定砷汞的含量.结果 铅、镉、砷、汞的回收率分别为107.3%、92.6%、90.2%、96.4%.结论 该法操作简便、快速,可用于中药材及成药中铅、镉、砷、汞残留量的测定.     

ICP-MS测定斑蝥中砷、铅、镉、汞含量不确定度的研究

目的 建立ICP-MS测定斑蝥中砷、铅、镉、汞含量不确定度的方法。方法 采用ICP-MS测定斑蝥中砷、铅、镉、汞含量,依据JF1059-1999确定不确定度的各个分量并合成测量不确定度。结果 斑蝥中砷、铅、镉、汞的含量分别为(0.51±0.03),(0.24±0.02),(0.029±0.002),(0.046±0.005)mg·kg^-1。样品的消化、仪器的状态、曲线的拟合是斑蝥中常见有害元素含量分析的测量不确定度的主要因素。结论 选择合适的消解方法,确定仪器的状态,保证溶液的基体匹配是保证测量结果准确性的关键步骤。