六氯苯对离体鱼肝线粒体抗氧化酶的作用

采用差速离心法从鲫鱼肝脏中提取线粒体,用不同浓度(0,2,4,8,16,32mg/L)六氯苯对其体外染毒30min.测定线粒体超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性,用聚丙烯酰胺凝胶电泳法分析其同工酶谱,并检测线粒体中丙二醛(MDA)含量.结果显示,SOD和GSH-Px活性及其同工酶的活性表达均呈现出低浓度六氯苯作用下被激活,高浓度六氯苯作用下被抑制的变化趋势.在高浓度六氯苯(32mg/L)作用下线粒体中MDA含量显著增加.说明六氯苯的毒性作用可能为一种自由基机制,即低浓度的六氯苯导致线粒体内活性氧自由基(ROS)生成量少量增加,SOD和GSH-Px及其同工酶活性由于氧化应激的诱导被激活;随着六氯苯浓度增加,线粒体内ROS生成量大量增加,并破坏了SOD和GSH-Px的抗氧化活性,导致其活力下降或丧失,自由基含量增加,线粒体脂质过氧化加剧.     

Effects of chitosan on growth of an aquatic plant （Hydrilla verticillata） polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, HydriUa verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand （COD）. Superoxide dismutase （SOD） activity and malondialdehyde （MDA） contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD （980 rag/L） and decreased with low COD （63 mg/L）, respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant ceils from the control experiment （untreated with chitosan） were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

Cobalt and manganese stress in the microalga Pavlova viridis （Prymnesiophyceae）： Effects on lipid peroxidation and antioxidant enzymes

Pollution of marine environment has become an issue of major concern in recent years.Serious environmental pollution by heavy metals results from their increasing utilization in industrial processes and because most heavy metals are transported into the marine environment and accumulated without decomposition.The aim of the present study is to investigate the effects on growth,pigments, lipid peroxidation,and some antioxidant enzyme activities of marine microalga Pavlova viridis,in response to elevated concentrations of cobalt(Co)and manganese(Mn),especially with regard to the involvement of antioxidative defences against heavy metal-induced oxidative stress.In response to Co~(2 ),lipid peroxidation was enhanced compared to the control,as an indication of the oxidative damage caused by metal concentration assayed in the microalgal cells but not Mn~(2 ).Exposure of Pavlova viridis to the two metals caused changes in enzyme activities in a different manner,depending on the metal assayed:after Co~(2 )treatments,total superoxide dismutase(SOD)activity was irregular,although it was not significantly affected by Mn~(2 )exposure.Co~(2 )and Mn~(2 )stimulated the activities of catalase(CAT)and glutathione(GSH),whereas,ghitathione peroxidase(GPX)showed a remarkable increase in activity in response to Co~(2 )treatments and decreased gradually with Mn~(2 )concentration,up to 50μmol/L,and then rose very rapidly,reaching to about 38.98% at 200μmol/L Mn~(2 ).These results suggest that an activation of some antioxidant enzymes was enhanced,to counteract the oxidative stress induced by the two metals at higher concentration.     

硒对汞胁迫小麦幼苗生理特性的影响

通过沙基培养研究不同ρ（Se）对Hg胁迫下小麦（Triticum aestivum L.）幼苗苗高、叶绿素相对含量（SPDA）、丙二醛（MDA）含量及抗氧化酶活性等的变化,探讨外加Se对Hg胁迫下小麦幼苗生理活性的影响。结果表明：单独ρ（Hg）=2.5 mg.L-1处理下,小麦幼苗叶绿素含量降低,SOD与CAT活性受到抑制降低,丙二醛（MDA）含量升高。ρ（Se）=5 mg.L-1和ρ（Hg）=2.5 mg.L-1共同处理下,叶绿素含量比Hg单独处理升高了7.6%,比对照升高了3.5%,MDA含量降低了38.8%,低于对照20.0%;外加ρ（Se）高于10 mg.L-1的处理中,叶绿素含量逐渐降低,MDA则呈升高趋势。ρ（Hg）=2.5 mg.L-1胁迫下低ρ（Se）=5~10 mg.L-1促进了SOD与CAT活性,其活性随Se质量浓度升高逐渐增强;ρ（Se）=10 mg.L-1和ρ（Hg）=2.5 mg.L-1共同处理下,两种酶活性比Hg单独处理分别升高了21.8%与32.8%,高ρ（Se）=15~20 mg.L-1处理下,两种酶活性则呈下降趋势。这些结果表明,不同ρ（Se）对Hg胁迫下小麦幼苗各生理指标具有显著影响,Se一定程度上缓解了Hg对小麦幼苗的毒害。     

氯氰菊酯暴露对龙须菜的胁迫影响

在实验室条件下研究了不同浓度氯氰菊酯胁迫下,龙须菜的生长状况及藻体生理生化指标变化情况.结果表明,龙须菜对氯氰菊酯敏感性较低,氯氰菊酯浓度低于100μg.L-1时对龙须菜生长的抑制作用不明显.在氯氰菊酯胁迫的24h内,龙须菜体内的叶绿素a、藻红蛋白、可溶性蛋白、可溶性糖含量以及超氧化物歧化酶(SOD)活性均呈现出低浓度(5或10μg.L-1)促进、高浓度(10或50μg.L-1)抑制的现象.在本研究设置的氯氰菊酯浓度下(1～100μg.L-1),膜脂过氧化产物丙二醛(MDA)含量均增加,呈现典型的剂量-反应关系,由氧自由基所引起的膜脂过氧化是氯氰菊酯对龙须菜产生毒害作用的重要原因.低浓度暴露早期SOD的激活以及蛋白质和糖类的促进作用对于抵抗氯氰菊酯的过氧化胁迫具有重要作用,但在高浓度氯氰菊酯胁迫下,SOD的失活致使氯氰菊酯对龙须菜产生明显毒性作用.     

Joint effects of cadmium and lead on seedlings of four Chinese cabbage cultivars in northeastern China

In northeastern China, large area of vegetable land has been simultaneously polluted by cadmium (Cd) and lead (Pb). Joint e ects of Cd and Pb on Chinese cabbage (Brassica pekinensis L.) were investigated using the seed germination and sand culture method. Four Chinese cabbage cultivars including Kangbingjinchun (KB), Dongyangchunxia (DY), Qinglvwang (QL) and Qiangshi (QS) from Shenyang in northeastern China were adopted in this study. The results showed that there were positive linear relationships between the inhibitory rate of biomass, root and shoot elongation and the concentrations of Cd and Pb. In particular, root elongation was more sensitive to joint stress of Cd and Pb. The activity of superoxide dismutase and the content of malondialdehyde (MDA), soluble protein (SP) and proline (PRO) changed significantly with increasing exposure concentration of Cd and Pb. The decrement in the activity of antioxidative enzymes, the content of SP and accumulation of MDA were relatively low in KB and QS. PRO played an important role in resisting Cd and Pb stress.     

商品氯氰菊酯农药对蛋白核小球藻的毒性效应研究

研究了氯氰菊酯对蛋白核小球藻(Chlorella pyrenoidosa)生长、细胞内含物(可溶性蛋白、可溶性糖)及抗氧化酶类(超氧化物歧化酶,SOD)、膜脂氧化产物(丙二醛,MDA)的影响.结果表明,在氯氰菊酯暴露下,藻细胞的生长受到不同程度的抑制,且抑制程度随氯氰菊酯浓度的增大而增大,氯氰菊酯对蛋白核小球藻生长的72h半效应浓度(EC50)为4.89mg·L-1.藻细胞所有生理生化指标对氯氰菊酯响应迅速,在暴露初期较为敏感,24h后趋于平稳.其中,可溶性糖和可溶性蛋白含量上升,中等浓度组(3.2,5.6mg·L-1)上升趋势最为显著.SOD活性则呈现出低浓度(1.0,1.8mg·L-1)促进、高浓度(>3.2mg·L-1)抑制效应.氯氰菊酯可使藻体内丙二醛(MDA)含量升高,氯氰菊酯浓度越高,藻体内MDA含量越高.研究结果表明,对藻细胞SOD活性的抑制及膜脂过氧化可能是氯氰菊酯对蛋白核小球藻产生毒害作用的重要原因.     

邻苯二甲酸二异壬酯致小鼠肾组织氧化损伤的研究

邻苯二甲酸二异壬酯是一种新型替代增塑剂,对其毒性研究已受到广泛关注。为探究邻苯二甲酸二异壬酯对肾组织的氧化损伤作用,将昆明小鼠随机分为5组,包括1个阴性对照组、4个邻苯二甲酸二异壬酯染毒组,按0.5、5、50和500 mg·kg-1四个剂量水平灌胃染毒14天。制备小鼠肾组织切片进行病理学观察,以肾组织匀浆测定活性氧(reactive oxygen species,ROS)、还原型谷胱甘肽(glutathione,GSH)、丙二醛(malondialdehyde,MDA)和8-羟基脱氧鸟苷(8-hydroxy-2-deoxyguanosine,8-OHd G)的含量,以肾组织细胞悬液测定DNA-蛋白质交联(DNA-protein Crosslink,DPC)系数。随着邻苯二甲酸二异壬酯染毒剂量的升高,小鼠肾组织的损伤程度加重,ROS、MDA、8-OHd G含量和DPC系数逐渐上升,GSH含量逐渐降低,各指标均呈一定剂量-效应关系。染毒剂量为5 mg·kg-1时,ROS、DPC系数差异有统计学意义(P0.05,P0.01);染毒剂量为50 mg·kg-1和500 mg·kg-1时,ROS、GSH、8-OHd G、MDA含量和DPC系数差异均有统计学意义(P0.05,P0.01)。结果表明较高剂量(≥50 mg·kg-1)邻苯二甲酸二异壬酯可造成小鼠肾组织氧化损伤。     

Phytotoxicity in seven higher plant species exposed to di-n-butyl phthalate or bis (2-ethylhexyl) phthalate

We investigated phytotoxicity in seven plant species exposed to a range of concentrations (0– 500 mg·kg⁻¹ soil) of di-n-butyl phthalate (DnBP) or bis (2-ethylhexyl) phthalate (DEHP), two representative phthalate esters (PAEs) nominated by USEPA as priority pollutants and known environmental estrogens. We studied seed germination, root elongation, seedling growth, biomass (fresh weight, FW) and malondialdehyde (MDA) content of shoots and roots of wheat (Triticum aestivum L.), alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne), radish (Raphanus sativus L.), cucumber (Cucumis sativus L.), oat (Avena sativa) and onion (Allium cepa L.), together with monitoring of plant pigment content (chlorophyll a, b and carotinoids) in alfalfa, radish and onion shoots. Root elongation, seedling growth and biomass of the test species were generally inhibited by DnBP but not by DEHP, indicating a lower level of phytotoxicity of DEHP than of DnBP. MDA contents of four species were promoted by PAE exposure, but not in alfalfa, ryegrass or onion shoots, indicating lower sensitivity of these three species to PAE pollutants. Plant pigment contents were clearly affected under the stress of both pollutants, implying the potential damage to the photosynthetic system of test plants, mainly by decreasing the content of chlorophyll a and b. Results of DnBP and DEHP phytotoxicity to the primary growth of test plants has provided information for the assessment of their environmental risk in the soil and also forms a basis for the further analysis of their toxic effects over the whole growth period of different plant species.     

三丁基锡对文蛤鳃的抗氧化酶活性及脂质过氧化的影响

在实验室条件下,观察质量浓度分别为高、中、低(0·1,1,10ng·L-1(以Sn计))3组的三丁基锡(TBT)暴露2、8、20d以及恢复7d和20d后对文蛤鳃的谷胱甘肽硫转移酶(GST)、过氧化氢酶(CAT)活性以及丙二醛(MDA)含量、还原型谷胱甘肽(GSH)含量的影响.结果显示,除了高浓度TBT(10ng·L-1)暴露在早期(2d)对GSH含量、GST和CAT活性产生抑制之外,TBT暴露对GSH含量、GST和CAT活性的作用主要为诱导效应.在暴露8d后,MDA的含量表现出显著的诱导.恢复7d后除了高浓度组对MDA还有影响外,其它各指标均恢复到与对照组相当的水平.结果表明,环境水平的TBT暴露对文蛤产生明显的氧化胁迫,抗氧化防御系统可以作为海洋环境有机锡污染监测的潜在的生物标志物.