Activity and heavy metal resistance of non-specific esterases in leaf beetle Chrysomela lapponica from polluted and unpolluted habitats

We compared the general activity and heavy metal resistance of non-specific esterases in two populations of the leaf beetle Chrysomela lapponica from habitats severely contaminated by heavy metals (mostly Ni and Cu) and two populations from unpolluted habitats. Concentrations of Ni and Cu in adult beetles from the most polluted site were 7.7 and 3.6 times higher that in beetles from unpolluted habitats. Larval esterases showed higher activity and lower susceptibility to heavy metals than esterases of adults. Larval esterase activity did not differ between populations from polluted and unpolluted sites, but adult beetles from polluted localities had lower esterase activity than beetles from unpolluted habitats. Both Cu and Ni sulfates in millimolar concentrations in vitro suppressed esterase activity of larvae from unpolluted habitats, but caused no negative effect on esterases of larvae from polluted sites. Similarly, inhibition of adult esterase activity by Ni was stronger in beetles from unpolluted localities than in beetles from polluted localities. This indicates that resistance of non-specific esterases to heavy metals is higher in leaf beetle populations from contaminated environment.     

Population-related molecular responses on the effect of pesticides in Carassius auratus gibelio

The aim of this study was to evaluate population-related peculiarities of the adaptive responses of Carassius auratus gibelio. In order to do this, male specimens from polluted (B) and clean (Z) sites were exposed to commercial pesticides thiocarbamate Tatoo (9.1 μg·L(-1)and 91 μg·L(-1)) or tetrazine Apollo (2 μg·L(-1) and 10 μg·L(-1)) during fourteen days. The control fish from site B was distinguished by weakness of antioxidant defence (measured from superoxide dismutase and catalase activities, redox index of glutathione (GSH), superoxide anion (O(2)) and lipid peroxidation levels), imbalance of the concentrations of protein metallothionein (MT-SH) and MT-related metals (MT-Me) and neurotoxicity. Differences in glutathione-S-transferase activity in the liver and vitellogenin-like proteins in the serum were also showed between B and Z control groups. Common effects of pesticides were related to a decrease in GSH, an increase in O(2) production, ethoxyresorufin O-deethylase activity and hepatosomatic index. Apollo provoked particular elevation of MT-SH/MT-Me ratio. Population-related difference in the response was the activation of antioxidant defence in fish from site B and its inhibition in fish from site Z. The genotoxic effect of exposures was more expressed in fish from site B. Principal component analysis combine all exposed groups from site Z and control group from site B in one set, and separated each exposed group from site B. The main distinguishing index of each population selected by classification and regression tree analysis was MT-SH.     

Distribution and assessment of heavy metals in the aquatic environment of Lake Manzala,Egypt

Analysis of trace metals from sediment and fish collected from eight locations in Lake Manzala, Egypt, during May, June and July of 2011, indicated anthropogenic impacts. The highest concentrations of metals, except Mn and Sr, were detected at Bahr Al-Baqar (S1) which drains from Cairo. At the other sampling locations, the concentrations of selected trace metals fall below the levels of concern while the geo-accumulation index (I_geo) suggests unpolluted conditions for the majority of the studied metals at most sites. However, near the Bahr Al-Baqar (S1) drain concentrations of Ag, Hg and Zn fall above the Long and Morgan's (1990) effects range low (ERL) while Pb was above their effects range median (ERM). I_geo values suggest unpolluted to moderately polluted condition for As and Sn, moderately polluted conditions for Zn, moderate to extremely polluted conditions for Ag, and severely to extremely polluted conditions for Pb at Bahr Al-Baqar. Two sites (Legan, S5, and Al-Ginka, S8) were indicated by I_geo as moderately polluted for Ag while two other sites (West of Bashar, S3, and Al Dehdy, S6) were indicated as unpolluted to moderately polluted for Ag. The Legan and Al-Ginka sites were also indicated as being moderately polluted for Zn. Similar to the sediments, the highest concentrations of metals in fish tissue were from Bahr Al-Baqar (S1). Al concentrations at all sites were comparable to concentrations known to cause lesions in fish. At all sites concentrations of selected trace metals in fish tissue were below the limits set by the FAO.     

Heavy metal pollution in Antarctica: a molecular ecotoxicological approach to exposure assessment

Trematomus bernacchii sampled from two sites at Ross Island, Antarctica, were assessed for condition (gonadal and hepatic somatic indices and condition factor), pathological state (liver and gill histology), hepatic metal (Zn, Cu, Cd and Ni) concentrations, and metallothionein induction by quantitative competitive (qc) RT-PCR. Fish from a polluted site (Winter Quarters Bay) had pathological anomalies including necrosis and periductal inflammation in their livers, and X-cell disease, epithelial hyperplasia, lamellar fusion and aneurysms in their gills. Such anomalies were less common in fish from a relatively pristine site (Backdoor Bay, Cape Royds). Fish from both sites had similar liver concentrations of Zn, Cu and Cd and qcRT-PCR revealed similar levels of hepatic metallothionein mRNA. Ni in the livers of fish from Winter Quarters Bay were higher than those in fish from Backdoor Bay, but the differences were not great enough to affect hepatic metallothionein mRNA significantly. Despite the polluted state of Winter Quarters Bay waters, it seems that the heavy metals present may have only limited impact on the health status of fish collected from this locality. This may reflect a low bioavailability of the heavy metals in Ross Island marine sediments and suggests that other factors, such as relatively high levels of organic pollutants (PAHs, PCBs) or pathogens from the nearby sewage outlet, may play a more significant role in the aetiology of pathological conditions in fish from Winter Quarters Bay.     

Age- and tissue-dependent metallothionein and cytosolic metal distribution in a native Mediterranean fish, Mullus barbatus, from the Eastern Adriatic Sea

The levels of metallothionein (MT), a biomarker of metal exposure, and of cytosolic metals (Zn, Cu, Cd), known as MT inducers, were investigated as variables of age (1 to 8 years) and tissue mass (liver, kidney, brain) of red mullet (Mullus barbatus). Within the age from 1 to 8 years the most significant increase is evident for cytosolic Cd in liver (43-fold) and in kidney (5-fold). MT and essential metals are constant with age or slightly increased. Over the growth period, statistically significant MT and metal increase is evident only between 1 and 6-8 years old specimens, while for Cd in liver and kidney cytosol significant increase already exists at 4 years old specimens. Metal distribution in all tissues follows the order: Zn>Cu>Cd, with even 500-800 times lower Cd levels than essential metal levels. Consequently, MTs follow the levels of essential metals, Zn and Cu, indicating MT involvement in homeostasis of essential metals. In contrast to kidney and brain, hepatic MT levels are not age-dependent. Inclusion of hepatic MT measurements and the associated cytosolic metals will be useful in the assessment of long-term metal effects in demersal fish M. barbatus.     

Response of catalase activity to Ag+, Cd2+, Cr6+, Cu2+ and Zn2+ in five tissues of freshwater fish Oreochromis niloticus

Catalase (CAT, EC 1.11.1.6) is an important enzyme in antioxidant defense system protecting animals from oxidative stress. Freshwater fish Oreochromis niloticus were exposed for 96 h to different concentrations of Ag(+), Cd(2+), Cr(6+), Cu(2+) and Zn(2+), known to cause oxidative stress, and subsequently CAT activities in liver, kidney, gill, intestine and brain were measured. In vivo, CAT was stimulated by all metals except Ag(+) in the liver and the highest increase in CAT activity (183%) resulted from 1.0 mg Cd(2+)/L exposure, whereas 0.5 mg Ag(+)/L exposure resulted in a sharp decrease (44%). In tilapia kidney, cadmium and zinc had no significant effects on CAT activity, whereas 0.1 mg Cr(6+)/L exposure caused a decrease (44%). Cadmium and zinc did not significantly affect the CAT activity in gill; however, 0.5 mg Ag(+)/L exposure caused an increase (66%) and 1.5 mg Cr(6+)/L exposure caused a decrease (97%) in CAT activity. All metals, except Cu(2+)(41% increase), caused significant decreases in CAT activity in the intestine. In brain, 1.0 mg Zn(2+)/L resulted in an increase in CAT activity (126%), while 1.5 mg Ag(+)/L exposure caused a 54% decrease. In vitro, all metals -- except Ag(+) and Cu(2+) in kidney -- significantly inhibited the CAT activity in all tissues. Results emphasized that CAT may be considered as a sensitive bioindicator of the antioxidant defense system.     

Productivity differences between dandelion (Taraxacum officinale; Asteraceae) clones from pollution impacted versus non-impacted soils

Common dandelions (Taraxacum officinale Weber, sensu lato; Asteraceae) introduced to North America form an assemblage of asexual (agamospermous), clonal lineages derived from Eurasian mixed sexual and asexual populations. We investigated whether selection for more pollution tolerant clonal lineages occurs at polluted sites and selection for more pollution intolerant lineages occurs at unpolluted sites. We tested the above hypothesis by performing reciprocal greenhouse productivity experiments in which unique dandelion clones (12 clones, identified by DNA fingerprinting, from each site type) sampled from two unpolluted and two polluted (moderately enhanced Cu, Pb and Zn soil concentrations) sites were grown pairwise in both unpolluted (nutrient solution only) and polluted (nutrient solution + Cu, Pb and Zn) media (n?=?48 paired tests for each media type). Dandelion clones from polluted sites produced fewer and smaller leaves, shorter roots and smaller root diameters, reduced shoot and root dry weights, and reduced total biomass compared to clones from unpolluted sites when clones were grown in unpolluted-media (P?≤?0.05). In contrast, clones taken from unpolluted sites were shown to produce significantly fewer and shorter leaves, shorter roots and smaller root diameters, reduced shoot and root dry weights, reduced total biomass, a reduced shoot : root biomass ratio, and have much lower survival compared to clones from polluted sites when both were grown in polluted-media (P?≤?0.05). These results reveal that there was increased selection against unpolluted-site clonal lineages in polluted-media and against polluted-site clonal lineages in unpolluted-media. Across all treatments, clones from unpolluted sites growing in unpolluted-media had the highest proximate measures of fitness. Overall, these findings provide insight into the relationships among anthropogenic environmental contamination and the consequent effects of selective forces acting on dandelion clones and their population genetic architecture.     

Different responses of biochemical markers in frogs (Rana ridibunda) from urban and rural wetlands to the effect of carbamate fungicide

Laboratory studies were conducted to determine the effects of carbamate fungicide TATTU (mixture of propamocarb and mancozeb, 0.091 mg L(-1)) on biochemical markers of exposure in Rana ridibunda from clean (reference) and polluted sites. The untreated animals from the polluted site had lower Cu,Zn- and Mn-superoxide dismutase (SOD) and acetylcholinesterase activity, the levels of lipid peroxidation products (TBARS) and protein carbonyls in the liver and vitellogenin-like proteins (Vtg-LP) in the serum, but higher levels of glutathione in the liver in comparison with untreated frogs from the reference site. Catalase activity, superoxide anion and metallothionein levels were the same in both groups. The animals from two sites demonstrate different response on the effect of TATTU during 14 days. In the frogs from polluted site the oxidative damage (the decrease of Mn-SOD activity, lipids and protein oxidative destruction), neurotoxicity (depletion of acetylcholinesterase activity), and endocrine disruption (increase of Vtg-LP level) were revealed. On the other hand, the part of the indices in the animals from the reference site was unchanged after the treatment and the level of metallothionein was elevated demonstrating the satisfactory ability for the adaptation to unfavourable conditions.     

Aluminium triggers genotoxic adaptation to methyl mercuric chloride and ethyl methane sulfonate, but not to maleic hydrazide in plant cells in vivo

Non-toxic, conditioning doses of aluminium chloride were tested for induction of adaptive response to the genotoxic challenge doses of methyl mercuric chloride (MMCl), maleic hydrazide (MH) and ethyl methane sulfonate (EMS). Embryonic shoot cells of Hordeum vulgare and root meristem cells of Allium cepa were employed as the assay systems. Plant tissues fixed at different recovery hours following the challenge treatments with or without prior Al-conditioning were analyzed for cells with genotoxicity markers that include spindle and/or chromosome aberrations and micronuclei (MNC). The results provided evidence that Al(3+) triggered adaptive response that protected the plant cells from the genotoxicity of MMCl and EMS. Al(3+), however, failed to induce adaptive response against the genotoxicity of MH. A comparison of Al-induced adaptive response with that induced by heavy metals: Cd(2+), Cu(2+), Hg(2+), Ni(2+), Pb(2+), Zn(2+) and oxidative agents: hydrogen peroxide (H(2)O(2)) and paraquat (PQ) pointed to the similarity of Al-adaptive response to that of PQ rather than to other heavy metals or H(2)O(2). Al-induced adaptive response demonstrated in the present study to MMCl and EMS possibly involved antioxidant defense and DNA repair systems, respectively.     

Mixed-function oxidase induction as a test for the biological monitoring of water: limitations and prospects]

The induction in fish liver of some enzyme activities, and typically of microsomal mixed-function oxidases (MFO), provides the earliest biological warning signal of exposure to pollutants. Our studies provided evidence that the basal levels of cytochrome P-450 and specific MFO activities, such as arylhydrocarbon hydroxylase (AHH) and ethoxyresorufin deethylase (EROD), were strongly influenced by the diet in freshwater fish (Oncorhynchus mykiss). The response of fish liver to a known enzyme inducer, i.e., beta-naphthoflavone, was also affected by the diet, which therefore should be carefully controlled in laboratory studies. Under field conditions MFO activities were significantly enhanced in the liver of O. mykiss kept in polluted river water as well as in the liver of the seawater fish Diplodus annularis collected from a polluted harbour area, as compared to specimens of the same species collected from an unpolluted reference area.     

Genotoxic damage in Solea senegalensis exposed to sediments from the Sado Estuary (Portugal): effects of metallic and organic contaminants

Juvenile Solea senegalensis (Senegalese sole) were exposed to freshly collected sediments from three sites of the Sado Estuary (West-Portuguese coast) in 28-day laboratory assays in order to assess the ecological risk from sediment contaminants, by measuring two genotoxicity biomarkers in peripheral blood: the percentage of Erythrocyte Nuclear Abnormalities (ENA) by use of an adaptation of the micronucleus test, and the percentage of DNA strand-breakage (DNA-SB) with the Comet assay. Sediments were surveyed for metallic (Cr, Ni, Cu, Zn, As, Cd and Pb) and organic (PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) and DDTs (dichloro-diphenyl-trichloroethane)) contaminants. Sediments from site A (farthest from hotspots of contamination) were found to be the least contaminated and weaker inducers of genotoxic damage, whereas sediments from sites B (urban influence) and C (affected by industrial effluents and agricultural runoffs) were responsible for a very significant increase in both ENA and DNA-SB, site B being most contaminated with metals and site C mainly with organic pollutants, especially PAHs and PCBs . Analysis of genotoxic effects showed a strong correlation between the concentrations of PAHs and PCBs and both biomarkers at sampling times T(14) and T(28), while the amounts of Cu, As, Cd and Pb were less strongly correlated, and at T(28) only, with ENA and DNA-SB. These results show that organic contaminants in sediment are stronger and faster acting genotoxic stressors. The results also suggest that metals may have an inhibitory effect on genotoxicity when interacting with organic contaminants, at least during early exposure. ENA and DNA-SB do not show a linear relationship, but a strong correlation exists between the overall increase in genotoxicity caused by exposure to sediment, confirming that they are different, and possibly non-linked effects that respond similarly to exposure. Although the Comet assay showed enhanced sensitivity, the two analyses are complementary and suitable for the biomonitoring of sediment contaminants in a benthic species like S. senegalensis.     

Genetic variation and heavy metal tolerance in the ectomycorrhizal basidiomycete Suillus luteus

Twenty-one isolates of the ectomycorrhizal fungus Suillus luteus were screened for their tolerance to the heavy metals Zn, Cd, Cu and Ni, measured as inhibition of radial growth and biomass production. Two populations from even-aged pine stands were investigated: 10 isolates were obtained from an area polluted with high levels of Zn, Cd and Cu, and 11 isolates were obtained from a control population located in a nearby unpolluted area. RFLP patterns of the internal transcribed spacer region of the isolates confirmed the morphological identification of the carpophores. All isolates were maintained on basic medium without elevated metals to avoid phenotypically acquired metal tolerance. The in vitro Zn and Cd tolerance of the S. luteus isolates from the polluted habitat were significantly higher than the tolerances measured in the isolates from the nonpolluted site. This observation suggests that the elevated soil metal concentrations might be responsible for the evolution of adaptive Zn and Cd tolerance. Tolerance was maintained in an isolate not exposed to elevated metals for 3 yr. The two S. luteus populations did not differ in tolerance to Cu and Ni. The mechanisms for the adaptive Zn and Cd tolerance are not identical as there was no correlation between response to the two metals; the most Zn-tolerant isolate was the most sensitive for Cd in the metal-tolerant population. Zinc did not accumulate in basidiocarp tissue, whereas Cd levels in basidiocarps were significantly higher in the population on the polluted site. Inter-simple sequence-repeat fingerprints showed that 90% of the isolates were from different individuals. The genetic variation in the population from the unpolluted site was considerably larger than that observed at the polluted site.     

Inhibition of Na+/K(+)-ATPase and Mg(2+)-ATPase by metal ions and prevention and recovery of inhibited activities by chelators

Kinetics and inhibition of Na(+)/K(+)-ATPase and Mg(2+)-ATPase activity from rat synaptic plasma membrane (SPM), by separate and simultaneous exposure to transition (Cu(2+), Zn(2+), Fe(2+) and Co(2+)) and heavy metals (Hg(2+) and Pb(2+)) ions were studied. All investigated metals produced a larger maximum inhibition of Na(+)/K(+)-ATPase than Mg(2+)-ATPase activity. The free concentrations of the key species (inhibitor, MgATP(2-), MeATP(2-)) in the medium assay were calculated and discussed. Simultaneous exposure to the combinations Cu(2+)/Fe(2+) or Hg(2+)/Pb(2+) caused additive inhibition, while Cu(2+)/Zn(2+) or Fe(2+)/Zn(2+) inhibited Na(+)/K(+)-ATPase activity synergistically (i.e., greater than the sum metal-induced inhibition assayed separately). Simultaneous exposure to Cu(2+)/Fe(2+) or Cu(2+)/Zn(2+) inhibited Mg(2+)-ATPase activity synergistically, while Hg(2+)/Pb(2+) or Fe(2+)/Zn(2+) induced antagonistic inhibition of this enzyme. Kinetic analysis showed that all investigated metals inhibited Na(+)/K(+)-ATPase activity by reducing the maximum velocities (V(max)) rather than the apparent affinity (Km) for substrate MgATP(2-), implying the noncompetitive nature of the inhibition. The incomplete inhibition of Mg(2+)-ATPase activity by Zn(2+), Fe(2+) and Co(2+) as well as kinetic analysis indicated two distinct Mg(2+)-ATPase subtypes activated in the presence of low and high MgATP(2-) concentration. EDTA, L-cysteine and gluthathione (GSH) prevented metal ion-induced inhibition of Na(+)/K(+)-ATPase with various potencies. Furthermore, these ligands also reversed Na(+)/K(+)-ATPase activity inhibited by transition metals in a concentration-dependent manner, but a recovery effect by any ligand on Hg(2+)-induced inhibition was not obtained.     

Genotoxic damage in Solea senegalensis exposed to sediments from the Sado Estuary (Portugal): Effects of metallic and organic contaminants

Juvenile Solea senegalensis (Senegalese sole) were exposed to freshly collected sediments from three sites of the Sado Estuary (West-Portuguese coast) in 28-day laboratory assays in order to assess the ecological risk from sediment contaminants, by measuring two genotoxicity biomarkers in peripheral blood: the percentage of Erythrocyte Nuclear Abnormalities (ENA) by use of an adaptation of the micronucleus test, and the percentage of DNA strand-breakage (DNA-SB) with the Comet assay. Sediments were surveyed for metallic (Cr, Ni, Cu, Zn, As, Cd and Pb) and organic (PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) and DDTs (dichloro-diphenyl-trichloroethane)) contaminants. Sediments from site A (farthest from hotspots of contamination) were found to be the least contaminated and weaker inducers of genotoxic damage, whereas sediments from sites B (urban influence) and C (affected by industrial effluents and agricultural runoffs) were responsible for a very significant increase in both ENA and DNA-SB, site B being most contaminated with metals and site C mainly with organic pollutants, especially PAHs and PCBs . Analysis of genotoxic effects showed a strong correlation between the concentrations of PAHs and PCBs and both biomarkers at sampling times T₁₄ and T₂₈, while the amounts of Cu, As, Cd and Pb were less strongly correlated, and at T₂₈ only, with ENA and DNA-SB. These results show that organic contaminants in sediment are stronger and faster acting genotoxic stressors. The results also suggest that metals may have an inhibitory effect on genotoxicity when interacting with organic contaminants, at least during early exposure. ENA and DNA-SB do not show a linear relationship, but a strong correlation exists between the overall increase in genotoxicity caused by exposure to sediment, confirming that they are different, and possibly non-linked effects that respond similarly to exposure. Although the Comet assay showed enhanced sensitivity, the two analyses are complementary and suitable for the biomonitoring of sediment contaminants in a benthic species like S. senegalensis.     

Distribution of bacterial plasmids in clean and polluted sites in a South Wales river.

We isolated 400 aerobic heterotrophic bacteria from the sediment of unpolluted and polluted sites in a fast-flowing south Wales river. Isolates were subjected to taxonomic tests and screened for the presence of plasmid DNA by alkaline lysis and agarose gel techniques. There were no significant differences between sites in either the total percentage of isolates containing plasmids (unpolluted site, 9.4%; polluted site, 15%) or in the percentage of non-Pseudomonas-like isolates containing plasmids (unpolluted site, 15%; polluted site, 10%). There were significantly more Pseudomonas-like isolates with plasmids at the polluted site than at the unpolluted site (unpolluted site, 7%; polluted site, 18%). This presumably reflected a response of the nutritionally versatile Pseudomonas-like isolates to conditions at that site. The majority (86%) of the plasmids detected had molecular masses between 35 and 312 megadaltons. These plasmids were large enough to carry genes for conjugal transfer, suggesting the possibility of such transfer in this environment.     

Specific regions in the Sod1 locus of the ericoid mycorrhizal fungus Oidiodendron maius from metal-enriched soils show a different sequence polymorphism

The huge diversity of fungi may reflect both the heterogeneity of the niches they occupy and the diverse stresses they must cope with. In order to investigate the genetic and functional diversity in the ericoid mycorrhizal fungus Oidiodendron maius subjected to heavy metal stress, we isolated O. maius strains from a serpentine site naturally enriched by heavy metals. Despite the high Cr and Ni soil concentrations, a high level of diversity was found in the serpentine fungal community. The growth of these isolates in the presence of different metal contaminants identified some tolerant strains, suggesting a site-specific adaptation. To investigate within-species gene divergence in stressful environments, we then compared the sequence polymorphism of a neutral (internal transcribed spacer) and a functional (Cu,ZnSOD) gene in O. maius isolates derived from the serpentine site, from a site heavily polluted with industrial wastes and from unpolluted sites. For all isolates tested, the polymorphism was higher in the nucleotide sequence of the functional gene. However, when compared with isolates from the serpentine area, isolates from industrially polluted sites showed a significantly higher polymorphism in the Cu,ZnSOD promoter region, suggesting that environmental stress may influence the rate of mutations in specific regions of the Sod1 locus.     

上海市小羽藓属植物重金属含量及其与环境的关系

应用原子吸收法对上海市13个样点的小羽藓植物体及相应土壤样品中的Cu、Pb、Cd、Zn、Cr 5种重金属元素含量进行了测定.通过对植物体内含量的聚类分析,将13个样点按重金属污染程度的轻重分为3个组：1)污染严重点,包括桂林公园、复兴公园、光启公园3个样点,均位于市区交通繁忙地带,其小羽藓体内重金属含量分别为：Cu 35.25～50.36 mg·kg^-1、Pb 55.50～65.00 mg·kg^-1、Cd 1.68～2.30 mg·kg^-1、Zn 829.63～1140.13 mg·kg^-1、Cr 7.41～16.41 mg·kg^-1;2)污染点,包括长风公园、古钟园、中山公园、和平公园、上海师范大学徐汇校区5个样点,均位于市区近郊,小羽藓体内重金属含量分别为：Cu 18.51～62.50 mg·kg^-1、Pb 14.38～34.25 mg·kg^-1、Cd 0.81～1.40 mg·kg^-1、Zn 354.25～671.75 mg·kg^-1、Cr 3.62～25.08 mg·kg^-1;3)相对清洁点,包括佘山、大观园、罗泾、植物园、崇明东平国家森林公园5个样点,位于上海市远郊,小羽藓体内重金属含量分别为：Cu 11.13～16.41 mg·kg^-1、Pb 4.63～27.25 mg·kg^-1、Cd 0.93～1.28 mg·kg^-1、Zn 489.25～1 086.75 mg·kg^-1、Cr 1.53～7.62 mg·kg^-1.结果表明,小羽藓属苔藓植物可作为监测上海地区环境重金属污染的良好指示植物.苔藓植物体内重金属含量水平与土壤重金属含量存在一定的相关性,而且也受其他因素的影响.     

Copper transporter 1, metallothionein and glutathione reductase genes are differentially expressed in tissues of sea bream (Sparus aurata) after exposure to dietary or waterborne copper

The high affinity copper transporter 1 (Ctr1), metallothionein (MT) and glutathione reductase (GR) are essential for copper uptake, sequestration and defense respectively. Following rearing on a normal commercial diet (12.6+/-0.2 mg kg(-1) Cu), sea bream were fed an experimental control diet lacking mineral mix (7.7+/-0.3 mg kg(-1) Cu), an experimental diet enhanced with Cu (135+/-4 mg kg(-1) Cu) or an experimental diet (7.7+/-0.3 mg kg(-1) Cu) whilst exposed to Cu in water (0.294+/-0.013 mg L(-1)). Fish were sampled at 0, 15 and 30 days after exposures. Fish fed the Cu-enhanced experimental diet showed lower levels of expression of Ctr1 in the intestine and liver compared to fish fed control experimental diets, whilst Ctr1 expression in the gill and kidney was unaffected by excess dietary Cu exposure. Waterborne-Cu exposure increased Ctr1 mRNA levels in the intestine and the kidney compared to experimental controls. Excess dietary Cu exposure had no effect on levels of metallothionein (MT) mRNA, and the only effect of dietary excess Cu on glutathione reductase (GR) mRNA was a decrease in the intestine. Both MT mRNA and GR were increased in the liver and gill after waterborne-Cu exposure, compared to levels in fish fed experimental control low Cu diets. Thus, Ctr1, MT and GR mRNA expression in response to excess Cu is dependent on the route of exposure. Furthermore, the tissue expression profile of sea bream Ctr1 is consistent with the known physiology of copper exposure in fish and indicates a role both in essential copper uptake and in avoidance of excess dietary and waterborne copper influx.     

Metallothioneins and energy budget indices in cadmium and copper exposed spiders Agelena labyrinthica in relation to their developmental stage, gender and origin

The aim of our studies was to explain the role of metallothioneins (MTs) in the neutralization of excessive amounts of metals (essential: copper (Cu) and toxic: cadmium (Cd)) and to describe the energy status in metal-exposed spiders Agelena labyrinthica in relation to its developmental stage, gender and origin. Juvenile, female and male spiders were collected from three variously polluted habitats, transferred to the laboratory and exposed to the metals in their diet. Cu and Cd accumulation in the body and exuviae, bioaccumulation factor, percentage of metallothionein positive cells, MT concentration, percentage of cells with depolarized mitochondria, ATP concentration and ADP/ATP ratio were measured and calculated. Cu appeared to be regulated and its excess is eliminated via, among others, the molting process, while Cd was rather accumulated by the spiders. The level of MTs increased significantly mainly in females exposed to both metals, irrespectively of the pollution degree of their site of origin, indicating a defensive role of the proteins. In general, even if both the MT level and the energy status indices were positively correlated with Cd and Cu concentrations in the spider body, the energy status of A. labyrinthica did not seem disturbed.     

镉致黑斑蛙肝脏氧化损伤与金属硫蛋白含量的变化

为观察镉对黑斑蛙(Rana nigromaculata)肝脏脂质过氧化产物和金属硫蛋白含量的影响,将黑斑蛙暴露于10.0mg·mL-1浓度的镉溶液中30d,分别测定了黑斑蛙在暴露4、10d和30d时肝脏组织中镉(Cd)、还原型谷胱甘肽(GSH)、金属硫蛋白(MT)和过氧化产物丙二醛(MDA)的含量。实验结果表明,黑斑蛙肝脏中镉的积累量、GSH和MT含量均随着镉暴露时间的延长而显著升高,具有明显的时间-效应关系;在镉暴露的第10天,肝MDA含量明显高于对照组。提示镉可对黑斑蛙肝脏造成氧化损伤,而GSH、MT含量的升高则可能是机体抗氧化损伤的机理之一。