五溴联苯醚-镉胁迫下蚯蚓抗氧化防御反应

文章采用自然土壤染毒法,研究了Cd2+和DE-71对蚯蚓体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性的影响。结果表明,两种污染物对蚯蚓的三种酶活性均产生一定的影响,DE-71主要表现为诱导效应,而高浓度的Cd2+则会产生抑制作用,SOD和CAT较POD敏感,对环境污染有很好的指示作用。Cd2+和DE-71复合染毒对抗氧化防御系统产生一定的联合毒性效应,SOD主要由协同转变为拮抗作用;以CAT指示的联合效应则受DE-71染毒浓度的影响,当Cd2+与10和100mg/kg(干重)DE-71复合时,联合毒性作用由协同转变为拮抗,而与400mg/kg(干重)DE-71复合时则呈现协同作用;POD指标下两种污染物间则表现为拮抗作用。总体来说Cd2+与DE-71对蚯蚓的抗氧化防御反应主要表现为拮抗效应。     

镉、苯并(a)芘胁迫对双齿围沙蚕SOD、CAT活性及MDA含量的影响

为评估重金属、多环芳烃单一及复合污染对海洋多毛类抗氧化酶活性及膜脂过氧化水平的影响,分别以镉(Cd)、苯并(a)芘(B[a]P)作为重金属和多环芳烃的代表,研究了Cd、B[a]P及二者复合污染胁迫下双齿围沙蚕(Perinereis aibuhitensis)体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量的响应特征。结果显示:Cd污染胁迫下,双齿围沙蚕体内SOD、CAT活性与Cd没有明显的"剂量-效应"关系,MDA含量则随其浓度升高而升高;B[a]P污染胁迫下,SOD、CAT活性及MDA含量均表现出明显的"剂量-效应"关系;Cd和B[a]P复合污染胁迫下,双齿围沙蚕体内SOD活性低浓度下被诱导,高浓度下被抑制,而CAT活性则随暴露浓度升高先降低然后恢复至对照水平,MDA含量仅在高浓度下被显著诱导(P0.05)。本研究表明,Cd能够干扰B[a]P对沙蚕抗氧化系统的影响,二者复合污染胁迫表现为拮抗效应。     

铅对河南华溪蟹卵巢抗氧化酶活力和脂质过氧化水平的影响

采用亚急性毒性实验方法,研究了铅(Pb2+)对河南华溪蟹(Sinopotamon henanense)卵巢组织抗氧化酶活性与脂质过氧化产物的影响.实验设置了5个Pb2+浓度组(3.675、7.35、14.70、29.40和58.80mg·L-1)和1个空白对照组,在3个染毒时间(5、10和15d)下对超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)活力和丙二醛(MDA)含量进行了测定.结果显示,在不同浓度和不同暴露时间下,铅对河南华溪蟹卵巢SOD、CAT、GPx活力及MDA含量均有明显的影响.SOD、CAT活力表现为低浓度诱导激活,高浓度抑制,即先升后降的变化规律,GPx活力在5d和10d时表现出先升后降的趋势,在15d时活力不断下降,且SOD在10d、14.70mg·L-1Pb2+浓度组,CAT在5d、7.35mg·L-1Pb2+浓度组,GPx在10d、3.675mg·L-1Pb2+浓度组分别升至峰值,而卵巢MDA含量随染毒时间的延长和染毒浓度的升高逐渐增多,且在15d、58.80mg·L-1Pb2+浓度组中较对照组差异极显著。结果表明,Pb2+暴露对河南华溪蟹卵巢产生了明显的氧化胁迫作用,且抗氧化酶和脂质过氧化物水平可以作为重金属对水生生物毒理学研究的生物标志物.     

海洋污染对毛蚶过氧化氢酶影响研究

采用体内染毒实验，研究了海洋常见污染物O#柴油、二甲苯以及重金属镉（Cd^2 ）对毛蚶（Scpharca subcrenata)肌肉过氧化氢酶（CAT）活性的影响；并探讨了O#柴油、二甲苯体外染毒对毛蚶肌肉CAT活性的影响。结果表明：在实验剂量范围内，3种污染物在低浓度下对毛蚶肌肉组织中CAT活性均起诱导作用，高浓度则表现为不同程度的抑制作用；O#柴油、二甲苯体外染毒对毛蚶肌肉CAT活性均产生诱导作用；无论体外、体内染毒毛蚶肌肉CAT活性与各污染物浓度间均存在剂量/效应关系。     

镉胁迫对白三叶萌发种子生理特性的影响

通过水培的实验方法,研究镉(Cd)胁迫对白三叶(Trifolium repens L.)萌发种子生理特性的影响。结果表明:随Cd浓度增加,白三叶萌发种子生物量逐渐下降,MDA含量上升,超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)仍保持较高活性。Cd浓度在10~50μmol/L时,其MDA含量略微上升,SOD活性显著升高。Cd浓度在1 250μmol/L时,MDA含量显著上升,SOD活性下降但仍高于对照。抗坏血酸过氧化物酶(APX)在Cd浓度为10~250μmol/L时保持较高活性,1 250μmol/L时,其活性与对照相比有所下降。Cd处理下,白三叶萌发种子SOD、POD和CAT协同合作,有效清除其体内的活性氧(ROS),使MDA在一定Cd浓度范围内保持相对稳定,在减少其膜质过氧化损伤和增强其抗性等方面起重要作用,同时也说明白三叶在城市Cd污染土壤修复中具有良好的应用前景。     

红树蚬体内氧化逆境标志物对SCCPs暴露的响应

实验室条件下,观测不同剂量-时间短链氯化石蜡(SCCPs)暴露下红树蚬(Polymesoda erosa)血液及鳃组织的4种氧化逆境标志物(SOD、CAT、GST酶活性及MDA含量)的响应特征.结果表明:在低浓度(0.5,1mg/L)和中浓度(5mg/L)胁迫组,血液和鳃组织SOD、GST酶基本表现为随胁迫时间延长,酶活性逐渐上升的趋势;高浓度(10,20mg/L)胁迫组SOD、GST酶在胁迫初期表现出很高的活性,之后逐渐下降.CAT酶在胁迫初期(1d)就表现出最高的酶活性,之后酶活性逐渐降低并最终受到抑制.低浓度胁迫组MDA含量呈现上升-下降-上升的趋势;中等浓度及以上胁迫组,MDA含量持续升高.抗氧化系统在低于5mg/L的SCCPs胁迫组能够有效发挥作用,而高于此浓度的胁迫组,抗氧化系统经过初期的应急反应后,随胁迫时间延长逐渐被破坏.本文还探讨了利用红树蚬作为指示生物的可行性.     

菲和芘单一及复合污染对蚯蚓抗氧化酶活性和丙二醛含量的影响

采用自然土壤法,以蚯蚓体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量为指标,探讨了不同剂量、不同暴露时间菲(Pbe)和芘(Pyr)单一及复合污染胁迫对蚯蚓的毒性效应.结果表明.菲和芘单一作用时.SOD活性均表现为低剂量激活,高剂量抑制;而MDA含量在暴露2 d内明显增加,第14 d时与对照...     

镉胁迫对虾夷扇贝抗氧化防御系统的影响

实验研究了虾夷扇贝在96 h的急性毒性效应,以及不同浓度Cd2+(0,0.005,0.025,0.050,0.150和0.300 mg/L)对虾夷扇贝内脏团超氧化物岐化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽-过氧化物酶(GSH-PX)活力的影响,以探讨其用于污染暴露的生物标记的可行性。结果表明:虾夷扇贝96 h的LC50为1.73 mg/L;其95%的置信区间是1.58～1.90 mg/L;安全浓度为0.0173 mg/L。酶活力:0.025 mg/L及以上的各实验组SOD活力先上升后下降,在第3 d时达到峰值,与对照组呈显著差异(P<0.05);处理第6 d,各浓度组SOD活力有所下降,到第9 d时受到抑制;CAT活力在处理0.5 d时,0.025mg/L0、.150 mg/L和0.300 mg/L三个浓度组均受到显著诱导(P<0.05),处理第6 d时,各实验组酶活力开始受到抑制。两种酶对实验设计的Cd2+浓度反应敏感,呈现出"诱导-抑制"规律,对海洋Cd2+早期污染具有指示作用。GSH-PX对Cd2+污染没有SOD和CAT那样敏感,GSH-PX的各个实验组与对照组相比差异均不显著,因而它作为对海洋Cd2+早期污染指示物的意义不大。     

黑藻对十二烷基苯磺酸钠和多聚磷酸钠胁迫的响应

研究了在十二烷基苯磺酸钠(SDBS)和多聚磷酸钠(STPP)及其复合胁迫下,黑藻过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性变化及其耐受浓度.结果表明,POD活性随着处理浓度的增加而逐渐增大;CAT在低浓度胁迫时活性逐渐增加,在较高浓度胁迫时活性降低;实验初期(6h时),SOD活性逐渐升高,随着SDBS处理浓度的提高及时间延长,SOD活性下降,并且在8mg/L浓度处理72h,SOD失活.SDBS对黑藻SOD的抑制作用大于STPP.黑藻对SDBS的耐受浓度(8mg/L)明显小于STPP的耐受浓度(256mg/L).黑藻对SDBS和STPP复合胁迫的耐受浓度值为(32+64)mg/L.     

钝顶螺旋藻对Cd胁迫的生理反应

研究了钝顶螺旋藻在Cd胁迫下的生理指标的变化.结果表明,在CdCl2浓度为0～24 mg/L范围的Cd胁迫下,随着CdCl2浓度的增加,可溶性蛋白的含量明显低于对照组,抗氧化系统也受到了不同程度的影响.SOD(超氧化物歧化酶)和POD(过氧化物酶)活力呈先增后降趋势,其中POD活力增加的程度较大,最高可达对照的360%,最低也为对照组的262%.在0～24 mg/L浓度范围内,APX(抗坏血酸氧化酶)活力均低于对照组,但随CdCl2浓度的增加呈递增状态.CAT(过氧化氢酶)均高于对照组,整体呈增加的趋势.GSH-PX(谷胱甘肽过氧化物酶)活力均低于对照,最低降至对照组的25%.MDA(丙二醛)作为膜脂质过氧化的产物,其累积是Cd胁迫的突出的生理变化之一,MDA的含量与CdCl2的浓度呈正相关.     

镉和乙草胺复合污染对玉米生理特性的影响

采用盆栽试验,研究了镉与乙草胺复合污染对玉米幼苗MDA含量和抗氧化酶活性的影响。结果表明,镉单独处理,低浓度下MDA的含量变化不大,当镉浓度大于30 mg/kg时,MDA的含量急剧上升;超氧化物歧化酶SOD、CAT在浓度为30 mg/kg时活性达到最高,之后随浓度的增大,其活性逐渐降低;POD的活性随着镉浓度的增大逐渐升高,且100 mg/kg时达到最高。镉与乙草胺复合处理,低镉浓度下MDA的含量与对照组CK相比差异显著,处理浓度越大,MDA含量越高;SOD、CAT的活性变化趋势与单镉处理时相类似,但变化幅度更加明显;POD的活性则随着浓度的增大继续升高。镉与乙草胺复合处理对玉米幼苗的毒害程度要大于单镉处理,并且施加乙草胺的浓度越大,玉米受毒害程度越深。     

沉积物中三丁基锡对铜锈环棱螺肝胰脏抗氧化防御系统的影响

以铜锈环棱螺(Bellamya aeruginosa)为试验对象,采用人工添加TBT的自然沉积物对铜锈环棱螺进行静态暴露实验,研究了沉积物中不同浓度TBT长期暴露(30 d)对铜锈环棱螺肝胰脏的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽(GSH)的影响,以揭示TBT对它们影响的浓度效应关系。结果表明,沉积物中低浓度(100 ng/g)TBT对SOD、CAT和GSH没有影响。当TBT浓度为500～1000 ng/g时,SOD活性呈现浓度依耐性的升高。当TBT浓度为200～1000 ng/g时,CAT活性表现为浓度依耐性的升高。高浓度(2000 ng/g)TBT则导致SOD和CAT活性急剧下降,分别比对照下降了67.33%和54.87%。当TBT浓度为200～1000 ng/g时,GSH含量呈现浓度依耐性的下降,高浓度(2000 ng/g)TBT导致GSH含量急剧下降,比对照下降了76.87%。环境水平的TBT长期暴露对铜锈环棱螺肝胰脏产生了氧化胁迫,高浓度的TBT长期胁迫使肝胰脏受到了严重的氧化损伤。CAT和GSH可以用作环境水平TBT长期暴露的有效生物标志物。     

Cd、Cu单一污染对小麦体内活性氧消除系统影响

采用溶液培养法,研究不同浓度Cd、Cu单一污染对小麦SOD、POD、CAT活性及MDA含量的影响。结果表明:(1)SOD和CAT活性对Cd胁迫反应较敏感,而POD活性变化不大,叶片中有效的活性氧自由基清除系统的平衡被打破,MDA含量增加;(2)Cu胁迫下,小麦叶片中MDA含量的变化趋势与根部的相反,在Cu处理浓度为25、50mg/L时,叶片中有效的活性氧自由基清除系统的平衡未被打破,MDA含量保持在较低的水平;而根部恰好相反,该系统出现了失衡现象,MDA含量偏高。     

商陆耐重金属Cd关键酶抗氧化酶的研究

研究商陆(Phytolacca americana L.)对Cd胁迫的抗氧化酶响应,对于揭示其耐Cd机制具有重要意义.商陆幼苗在200μmol/L或400 μmol/L CdCl2营养液中处理4 d,叶片活性氧自由基和MDA含量升高,膜透性增加,光合速率降低,表明Cd胁迫诱导产生氧化胁迫.随着Cd处理含量的提高和时间的...     

四溴双酚A和镉复合污染对不同生物体的安全阈值

以赤子爱胜蚓（Eisenia fetida）、斑马鱼（Zebrafish）作为受试生物,进行急性毒性试验,死亡率、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）为效应指标,采用基准剂量（BMD）法推导四溴双酚A （TBBPA）和镉（Cd）单一及联合暴露对不同生物体的安全阈值.结果表明,在本研究的试验剂量范围内,蚯蚓、斑马鱼TBBPA、Cd暴露剂量与死亡率、SOD、CAT活性效应指标存在明显剂量-效应关系.单一暴露下,CAT、SOD活性指标最敏感,蚯蚓和斑马鱼的TBBPA安全阈值分别为0.95,0.44mg/L,Cd安全阈值分别为71.17,0.42mg/L.联合暴露下安全阈值小于单一暴露.蚯蚓、斑马鱼TBBPA安全阈值分别为0.33,0.024mg/L,Cd为6.45,0.176mg/L.     

Effects of phenanthrene on hepatic enzymatic activities in tilapia (Oreochromis niloticus♂×O. aureus♀)

The effects of phenanthrene (Phe) on hepatosomatic index (HSI) and hepatic enzymatic activities in hybrid tilapia (Oreochromis niloticus ♀× O.aureus ♂) were investigated via the static freshwater exposure at dosage of 50,100 or 400 μg/L for 4-14 d.Compared with the control group,HSI was significantly decreased (P<0.05) at 400 μg/L at day 14.Increased enzymatic activities (P<0.05) were observed for catalase (CAT),glutathione peroxidase μgPx) and superoxide dismutase (SOD) at either 100 or 400 μg/L at day 8 and 14,as well as for CAT at 50 μg/L at day 14,except for GPx at 400 μg/L at day 8.Ethoxyresorufin O-deethylase (EROD) activity was significantly increased (P<0.05) at all dosage at day 4 as well as at 50 μg/L at day 8,but significantly decreased at either 100 or 400 μg/L at day 14 (P<0.05).Glutathione-S-transferase μgST) activity was not affected.The results suggest that CAT,GPx,SOD and EROD,as well as HSI in tilapia may be used as the biomarkers or indexes for evaluating or monitoring the pollution of polycyclic aromatic hydrocarbons (PAHs) such as Phe.     

Interactions of zinc and cadmium toxicity in their effects on growth and in antioxidative systems in tomato plants (Solanum lycopersicum)

The interaction between zinc and cadmium was investigated in tomato plants (Solanum lycopersicum). Ten-day-old seedlings were treated with 10 μmol/L CDC12 associated to different concentrations of ZnC12 (10, 50, 100, and 150 μmol/L). Zn supply clearly reduced Cd accumulation in leaves and simultaneously increased Zn concentration. Cd induced oxidative stress in leaves as indicated by an increase in thiobarbituric acid-reactive substances (TBARS) level and chlorophyll breakdown. Furthermore, compared with control, Cdtreate plants had significantly higher activities of superoxide dismutase (SOD, EC 1.15.1.1), whereas, catalase (CAT, EC 1.111.1.6),ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2) activities were significantly suppressed by Cd addition. Zn supplementation, at low level, restored and enhanced the functional activity of these enzymes (SOD, CAT, APX and GR) as compared to Cd-alone-treated plants. The beneficial effect of adequate Zn level on Cd toxicity was confirmed by a significant decrease in TBARS level and restoration of chlorophyll content. However, when Zn was added at high level in combination with Cd there was an accumulation of oxidative stress, which was higher than that for Cd or excess Zn alone treatments. These results suggested that higher Zn concentrations and Cd are synergistic in their effect on plant growth parameters and oxidative stress.     

Study on the sensitivity to cadmium of marine fish Salaria basilisca（Pisces： Blennidae）

The present study tested the sensitivity of Salaria basilisca to water-cadmium (Cd) contamination. For this purpose, liver somatic index (LSI), Cd concentrations and the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured in the liver of S. basilisca exposed to Cd-contaminated water (2 mg Cd/L as CdCl2) for 14 and 28 d. The results showed that the LSI decreased significantly after 14 and 28 d of Cd-exposure. Cd bioaccumulation in the liver resulted in an increasing uptake up to 42 g/g dry weight after 28 d of exposure. Activities of CAT and SOD were significantly increased with increasing exposure time. A significant increase in GSH-Px activity, under Cd influence, was observed during 14-day exposure period (p < 0.0001). However, a significant decrease (p < 0.05) in this activity with respect to control fish was registered after 28 d of Cd-exposure. These results showed that Cd accumulation in the liver of S. basilisca could induce oxidative stress as demonstrated by changes in the antioxidant enzyme activities. Results also emphasized that S. basilisca may considered as a sensitive species to Cd exposure.     

Interactions of zinc and cadmium toxicity in their effects on growth and in antioxidative systems in tomato plants （Solanum lycopersicum）

The interaction between zinc and cadmium was investigated in tomato plants (Solanum lycopersicum). Ten-day-old seedlings were treated with 10 mol/L CdCl2 associated to di erent concentrations of ZnCl2 (10, 50, 100, and 150 mol/L). Zn supply clearly reduced Cd accumulation in leaves and simultaneously increased Zn concentration. Cd induced oxidative stress in leaves as indicated by an increase in thiobarbituric acid-reactive substances (TBARS) level and chlorophyll breakdown. Furthermore, compared with control, Cdtreated plants had significantly higher activities of superoxide dismutase (SOD, EC 1.15.1.1), whereas, catalase (CAT, EC 1.111.1.6), ascorbate peroxidase (APX, EC 1.11.1.11), and glutathione reductase (GR, EC 1.6.4.2) activities were significantly suppressed by Cd addition. Zn supplementation, at low level, restored and enhanced the functional activity of these enzymes (SOD, CAT, APX and GR) as compared to Cd-alone-treated plants. The beneficial e ect of adequate Zn level on Cd toxicity was confirmed by a significant decrease in TBARS level and restoration of chlorophyll content. However, when Zn was added at high level in combination with Cd there was an accumulation of oxidative stress, which was higher than that for Cd or excess Zn alone treatments. These results suggested that higher Zn concentrations and Cd are synergistic in their e ect on plant growth parameters and oxidative stress.