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1.
Variation in glycogen concentration, condition index (CI) and filtration activity were measured in the bivalve Macoma balthica buried in sediment and experimentally exposed to cadmium (Cd). The stress due to elevated but sub-lethal concentrations (300 ppb Cd) affected the overall fitness of the organism as all parameters monitored responded significantly. Lower concentrations tested (10, 30 and 100 ppb) only induced a significant decrease in filtration activity, which may play a protective role, enabling the organism to slow down its metabolic activity and preserving the integrity of its reserves (reflected by stable CI and glycogen levels). Hence, the various endpoints selected show different thresholds. Our results also demonstrate that under high exposure, small individuals loose proportionally more glycogen per unit of weight than larger ones, thus confirming the higher sensitivity of small individuals to metal contamination. Furthermore, exposure to intermediate concentration (30 ppb) seems to be beneficial to the small individuals as indicated by their high CI values compared to the control. These results showed thus that non-sigmoidal concentration–response relationship and sizes of individuals should be considered in monitoring programmes and risk assessment.  相似文献   

2.
亚心形扁藻超氧化物歧化酶活性对镉和铜的应答   总被引：3，自引：0，他引：3  
以亚心形扁藻为实验材料,对不同浓度重金属镉(Cd2 )和铜(Cu2 )作用下亚心形扁藻的超氧化物歧化酶(SOD)活性的变化和膜脂过氧化作用进行了探讨,以期了解藻类抗重金属的机制。结果表明:随着Cd2 和Cu2 浓度的增加亚心形扁藻的SOD的活性逐渐升高,但高浓度Cd2 可导致SOD活性活性下降。膜脂过氧化实验结果显示,半抑制浓度的重金属处理72hr后,膜脂过氧化产物丙二醛(MDA)显著提高。用72h半抑制浓度的重金属处理亚心形扁藻随时间的变化关系表明,在最初的12hr内SOD活性被两种重金属离子诱导迅速升高,然后逐渐趋于平稳。总之,SOD活性的变化与重金属的种类、浓度和处理时间有关。  相似文献   

3.
Shallow water hydrothermal vents can be compared to polluted places due to high concentrations of heavy metals, and are thus good models for bioaccumulation studies. The present study intended to estimate the time of exposure required for the accumulation of certain elements to stabilize in specimens of Cystoseira abies-marina , to be used as a reference in future work. Cystoseira abies-marina intertidal specimens were transplanted from Mosteiros (a non-hydrothermal and pristine site) to Ferraria (with hydrothermal activity) and left there. Transplanted samples were collected after 1, 2, 4 and 8 weeks and the concentrations of Cd, Mg, Mn and Zn were measured through flame atomic absorption spectrophotometry. Although further studies with increased periods of exposure are needed because the concentration of these elements never stabilized in the collected samples, there is strong evidence that increased time of exposure led to increased concentrations of Cd, Mg, Mn, but not Zn. These results are consistent with the assumption that C. abies-marina is bioaccumulating some of the heavy metals and can thus be a good indicator for polluted waters.  相似文献   

4.
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5.
Cadmium (Cd) accumulation and elimination were investigated in the tissues (gill, intestine, kidney, lever and muscle) of juvenile rockfish, Sebastes schlegeli, after sub-chronic dietary Cd exposure (0, 0.5, 5, 25 and 125 mg/kg). No mortality occurred during the sub-chronic exposure to dietary Cd. Specific growth rates of the rockfish estimated by weight and length were significantly different from those of the control, and a significant inverse relationship was observed between weight gain and the exposure concentration of dietary Cd at 25, 125 mg/kg. Cd accumulation in the tissues increased with exposure periods and concentrations for the 60 days of dietary Cd exposure. Cd accumulation in the intestine of rockfish was higher than other tissues, and the order of Cd accumulation in tissues were intestine>kidney approximately liver>gill>muscle. Accumulation factors showed an increase with the exposure period and an inverse relationship between the accumulation factor and the exposure concentrations in the gill, intestine, liver and muscle, but not in kidney. Cd elimination in tissues of rockfish decreased during the 30 days of depuration except kidney and muscle. Intestine showed the fastest elimination rates of Cd at all concentrations compared with other tissues.  相似文献   

6.
Dogwhelks Nucella lapillus feed mainly on mussels and barnacles, and may experience periods of starvation. We report effects of nutritional state and prey type on the survival, growth, cadmium (Cd) accumulation, metallothionein (MT) induction and glycogen stores in N. lapillus exposed to Cd in water. Adult dogwhelks, with similar shell length (30.0+/-1.5 mm), were either starved or fed to satiation with barnacles Semibalanus balanoides, mussels Mytilus edulis or Cd-dosed M. edulis, and kept in filtered natural seawater (< 0.01 microg Cd 1(-1)) or Cd-contaminated (400 microg Cd 1(-1)) seawater for 80 days. Mortality and individual growth rate were determined. Cd, MT and glycogen were measured in different tissues. Prolonged starvation and exposure to Cd significantly reduced the survivorship of N. lapillus, but feeding could help dogwhelks to combat Cd toxicity and minimise mortality. Extended starvation also caused tissue wastage, leading to higher concentrations of Cd and MT in tissues, whereas fed animals increased in weight and had lower Cd and MT concentrations because of the tissue dilution effect. Prey type significantly affected growth rate of dogwhelks and indirectly influenced Cd accumulation, MT induction and glycogen stores. Eating mussels promoted better growth and higher glycogen reserves than eating barnacles. Individual growth rate decreased with increasing Cd accumulation. Cd-exposed survivors grew faster and consumed more than control animals, implying that these survivors may have better fitness and greater tolerance to Cd toxicity. The use of growth, condition index, MT and glycogen as biomarkers of environmental pollution are discussed. These results indicate a need to incorporate biological data including growth (or at least condition index) and prey type into biomonitoring programmes to allow sound interpretation.  相似文献   

7.
The efficacy of the barnacle Balanus amphitrite as a bioindicator for Cd in the environment was investigated through simulation exercises in an ecotoxicological simulation model based on field data. The study showed in general that B. amphitrite is a good bioindicator to record mean trends of the Cd bioavailability in the environment. The model correct reflected differences between high and low patterns of Cd concentrations in the barnacle in the field, but it did not accurately reflect short-term temporal variations. A model investigation pointed out three issues that must be taken into account when using B. amphitrite as bioindicator for Cd bioavailability in the environment: (1) variations in the mean weight of the sampled population may affect the barnacle's Cd concentration determination, specially if a size effect for the metal concentration in the organism is not detected; (2) a sampling effort approximately 5 times greater than that of usually applied in such studies would be required to detect an environmental change that caused a realistic increase in the main source of Cd to the barnacle; and (3) barnacle tissue better responds to long-term changes in the Cd level of its sources.  相似文献   

8.
The bioaccumulation of four metals (Cd, Cu, Pb, Zn) dissolved in water was assessed measuring the concentrations recorded within sea-urchin larvae (Paracentrotus lividus, Lmk.) after a 48-h exposure period. Concurrently, the frequencies of abnormalities were evaluated at the 48-h pluteus stage to check the actual toxicity of such contaminants with regards to larval development. Maximum metal concentrations in the larvae reached 43.8 +/- 6.7 micrograms Cd g-1 dry weight (d.w.), 1269 +/- 392 micrograms Cu g-1 d.w., 3106 +/- 679 micrograms Pb g-1 d.w., 534 +/- 62 micrograms Zn g-1 d.w. Bioconcentration factors (BCFs) reached very high values for Pb (maximum value: 16,282 +/- 973) and indicated that the concentrations of Pb and Cd were directly related to the water concentration at least in the range of concentrations tested. Zn appeared to be partially regulated above a certain threshold concentration (between 5 and 25 micrograms l-1). Cu was accumulated with an active uptake at least below lethal threshold level (100 micrograms l-1). Nevertheless, above these thresholds, high mortality of embryos prevent any interpretation of Zn and Cu bioconcentration factors. Concurrent studies carried out on embryotoxicity confirmed the high toxicity of Cu towards sea-urchin pluteus larvae and highlighted the different behaviour of Cd. The internal Cd concentrations were directly related to the external ones, comparable to other non-essential metals, but Cd had little toxic effect on the initial larval development.  相似文献   

9.
In the present study the induction of metallothioneins (MTs) and its relation to cytosolic metal concentrations (Zn, Cu and Cd) in the euryhaline crustacean Neomysis integer exposed to Cd at different salinities was studied. N. integer was exposed to the same free cadmium ion activity of 5.74 x 10(-9) mol l(-1) (i.e. 1/5 of the 96 h LC(50) value expressed as cadmium activity) in hypo-osmotic (5 psu), isosmotic (16 psu) and hyper-osmotic media (25 psu) for 7 days. In this way, the effect of salinity on cadmium speciation was eliminated and therefore the physiological effect of salinity on Cd accumulation and MT induction could be studied. The accumulation of cytosolic Cd in N. integer changed with salinity from 1.11+/-0.05 micromol l(-1) at 5 psu up to 1.43+/-0.17 micromol l(-1) at 25 psu. This could indicate that the physiological response of euryhaline estuarine invertebrates like N. integer to salinity changes can influence the rate of trace metal uptake from solution. While the salinity changes did not cause significant differences in cytosolic Zn concentrations (mean value of all tested salinities: 34.4+/-2.8 micromol l(-1)), an inverse relationship between salinity and cytosolic Cu concentration was observed. The highest concentration of 15.7+/-2.3 micromol Cul(-1) was determined at 5 psu and the lowest 10.9+/-1.4 micromol Cul(-1) at 25 psu. This could point to a possible relationship between the copper concentration and the hemocyanin metabolism in N. integer. This is the first time that differential pulse voltammetry method was applied to MT assays with N. integer. Although the exposure to Cd resulted in a higher Cd cytosolic concentration, no subsequent MT increase was detected. The significant positive correlation between MT levels and cytosolic Cu concentrations (Spearman correlation coefficient r(s)=0.356, p=0.009) implies a strong relationship between MT and Cu in N. integer.  相似文献   

10.
The use of selected hematological and biochemical parameters as indicators of metal exposure in aquatic organisms was evaluated. The hematological and biochemical parameters examined include glucose, hematocrit and aminotransferase levels in golden shiners exposed to cadmium. Cadmium exposure produced significant alterations in the levels of glucose, aspartate aminotransferase and alanine aminotransferase; however, hematocrit was not altered by exposure to cadmium. In addition, the comparative activity of Na/K adenosine triphosphatase (ATPase) was evaluated in the fathead minnow, golden shiner and bluegill sunfish. Basal Na/K ATPase activity was lowest in golden shiner (1·01 μmol Pi/mg protein/h) and highest in bluegill sunfish (1·45 μmol Pi/mg protein/h). While a stimulation of Na/K ATPase activity was observed at an exposure concentration of 1 μg Cd/liter in the fathead minnow and bluegill sunfish, inhibition of enzymatic activity was observed at higher exposure concentrations (10 and 100 μg Cd/liter). Gill Na/K ATPase activity in golden shiner was not significantly influenced by cadmium exposure. The observed insensitivity of ATPase in shiner may, in part, be related to higher background and accumulated concentrations of cadmium in gill tissue.  相似文献   

11.
Laboratory bioassays were conducted to test the acute toxicity effects of sudden exposure to sodium cyanide (NaCN) on the endogenous rhythm of the oxygen consumption rate (OCR) in the black rockfishSebastes schlegeli. The OCR of the black rockfish (n = 14, total length = 20.4 ± 1.16 cm, wet weight = 158 ± 25 g) was measured with an automatic intermittentflow-respirometer. OCR decreased significantly when experimental fish were exposed to NaCN. When exposed to 10 ppb NaCN, fish were able to recover their OCR rhythmic activities. When fish were exposed to 20 ppb, however, the metabolic activity rhythms were not recovered. These results suggest that exposure to NaCN concentrations over 20 ppb cause severe physiological damage to the endogenous rhythms of black rockfish.  相似文献   

12.
The impact of dietary and water exposure on the accumulation and distribution of cadmium (Cd) in subcellular components of the polychaete Capitella sp. I was investigated. Worms were exposed to either dissolved Cd alone ('Water-Only' treatments; WO) or diet-bound Cd alone ('Algae-bound Only' treatments; AO). Thus, WO worms were starved and AO worms were fed. Differential centrifugation was used to fractionate worm homogenates into debris- (DE), mitochondrial- (MI), microsomal- (MC) and cytosolic- (CY) fractions, and the concentration of Cd in these fractions was quantified by radiometric analysis using the specific activity of the (109)Cd radioisotope. Neither exposure route nor Cd exposure affected the total protein content in the worms. However, fed, but not starved worms relocated proteins from the mitochondria to the cytosol in response to Cd exposure. In systems without Cd addition, starvation likewise influenced the distribution of protein between mitochondria and cytosol. Cutaneous uptake and accumulation of Cd from the water was related to surface area while dietary uptake was influenced by the amount of sediment passing through the gut. Irrespective of exposure route, Cd was accumulated primarily in the debris fraction although comparisons between the treatments indicated that relatively less Cd was located in DE and more in MI, MC and CY fractions in worms in AO compared to worms in WO. Cd per unit protein in DE and MI fractions was twice as high as in MC and CY fractions in WO, whereas MC contained the highest Cd content followed by MI, DE and CY fractions in AO worms. Our results stress the importance of exposure route for the internal distribution and toxicity of Cd to deposit feeders such as Capitella sp. I.  相似文献   

13.
Protein expression and lysosomal stability were observed in Mytilus edulis exposed to 0, 20, 40, 60, and 80 ppb copper sulfate for 24 h in a static exposure system. Haemolymph was removed from each mussel and analyzed for lysosomal damage using the Neutral Red retention assay expressed as the ratio of lysosomal size to cell area, the lysosomal destabilization ratio. Gill tissue from the same individuals was dissected, homogenized and the proteins extracted and then separated using two-dimensional gel electrophoresis. Two-dimensional protein maps from each concentration were analyzed using MELANIE II 2D gel analysis software (Biorad). Lysosomal damage increased with each dosage, with LDRs ranging from 0.18 +/- 0.01 at 0 ppb copper sulfate to 0.32 +/- 0.11 at 80 ppb copper sulfate. Orthogonal comparisons showed that the control, 20 and 40 ppb classes together differed significantly (P < 0.05) from the 60 and 80 ppb classes together. Specific protein expression signatures were identified at each dosage.  相似文献   

14.
A study was performed in the Tyrrhenian Sea in front of S. Rossore Park (Pisa) to ascertain the degree of Cu, Pb, Cd and Cr pollution and to investigate whether the rivers flowing into the sea may be considered potential sources of seawater contamination. Owing to the variability of such a system, the research, covering a one-year period, involved five surveys on 13 selected sampling stations and two surveys following the floats along the river Arno and its plume. The results refer to the total concentration of the above metals in the water phase after filtration. The content of Cu, Pb and Cd was always found to be higher than in the reference station (about 8 km offshore), generally reaching maximum values around the mouths of the rivers. Concentrations exceeding the minimal risk concentration were observed in the case of Cd. As for Cr, its concentration was always below the detection limit of the analytical method used. Rivers thus appear to be the main sources of coastal metal pollution.By the samplings carried out along the river Arno and its plume (involving 3–5 km from the mouth), it was found that the dilution model represents the concentration pattern for Cu and Pb fairly well over a large range of salinity.  相似文献   

15.
雷雯雯  徐团  王兰 《海洋与湖沼》2012,43(2):299-305
采用急性毒性实验方法,研究了不同浓度氯化镉(0、7.25、14.50、29.00、58.00和116.00mg/L)处理不同时间(1d、3d、5d和7d)对长江华溪蟹心肌细胞凋亡的影响。结果表明,低浓度组及染毒时间较短时镉对心肌的影响不明显,但随着染毒浓度的增加和时间的延长,心肌出现空泡变性、玻璃样变性、炎细胞浸润等病理现象,在染毒7d虽然观察到疑似的凋亡细胞,但凋亡率较低;荧光显微镜未观察到心肌细胞典型的凋亡细胞核形态学变化;琼脂糖凝胶电泳图谱未出现凋亡细胞所特有的梯状条带;流式细胞术检测结果显示镉处理组细胞凋亡率增加,但与对照组相比,无统计学意义(P>0.05);Caspase-3活性也没有显著性变化(P>0.05)。因此,在本实验所选取的浓度和时间范围内,镉未诱导长江华溪蟹心肌细胞发生细胞凋亡,这与本课题组前期研究中观察到的肝胰腺、精巢组织在染毒2d、7d发生细胞凋亡的情况明显不同,这可能与心脏组织的特殊性、不同组织对镉的积累量不同有关。  相似文献   

16.
The common guillemots, Uria aalge, found stranded at the Belgian coast, display high levels of Cu in both liver and kidneys. The condition index of the animals, defined as the ratio of liver to kidneys mass (Wenzel & Adelung, 1996, The suitability of oiled Guillemots (Uria aalge) as monitoring organisms for geographical comparisons of trace element contaminants. Archives of Environmental Contamination and Toxicology, 31, 368-377), influences both the metal concentration and its binding to metallothioneins (MT): the lower the condition index, the more emaciated the animals, and the higher the total Cu concentration and the concentration of Cu bound to MT. In less robust individuals, our results suggest that Cu could displace Zn from MT, rendering the Zn ions available to induce a new MT synthesis. Sex-related effects also emerged as significantly higher hepatic MT as well as Cu- and Zn-MT concentrations were found in emaciated male guillemots compared to females. In both organs, Cd concentrations remained low and typically demonstrated an age-dependent renal accumulation, with no noticeable effect of the condition index. As a whole, these results suggest that, for guillemots found stranded at the Belgian coast. Cu binding to hepatic and renal MT could function as a protective mechanism, rendering the metal ions unavailable to exert any cytotoxic activity.  相似文献   

17.
The concentrations of Pb, Cu, Cd and Zn were determined in above- and belowground parts of eelgrass (Zostera marina L.) at forty stations in a shallow, brackish water area (the Limfjord, Denmark). The concentrations of the trace metals were significantly elevated near the cities of Aalborg (Pb, Cu) and Struer (Cd). Trace metal concentrations in above and belowground parts of eelgrass were log-normal distributed and the concentrations of Cd, Cu and Zn in aboveground parts were significantly higher than in belowground parts. Furthermore, a significant correlation between trace metal concentrations in above- and belowground parts was found. The background level of trace metal concentrations in eelgrass in the Limfjord was estimated.The application of eelgrass as a monitoring organism is discussed; it is suggested that the concentration of some trace metals in above- and belowground parts of eelgrass may be used as a measure of the bioavailable fraction of these trace metals in ambient and interstitial water (sediment), respectively.  相似文献   

18.
Organisms have evolved a cellular response called stress protein response that increases their tolerance in adverse environmental conditions. Well known stress proteins that bind essential and toxic metals are metallothionein (MT). The scallop Mizuhopecten yessoensis is the most interesting organism because it is able to accumulate toxic cadmium in its digestive gland. However, in the tissue of the digestive gland of Mizuhopecten yessoensis MT (metallothioneins) have not been found. Eastern scallops, Mizuhopecten yessoensis, were collected from two locations ?? one clean and one polluted site. The concentrations of cadmium (Cd), copper (Cu) and zinc (Zn) were measured in the digestive gland. There was a significant increase in Cd concentrations in this studied tissue. We found that in the presence of cadmium Mizuhopecten yessoensis can induce high molecular proteins. The results of experiments have shown that Cd-binding ligands have a number of properties similar to MT: acetone and temperature stability; the ability to bind some metals, including Cd, Cu and Zn. Protein chromatography (FPLC, Superosa 12) from the digestive gland of scallop M. yessoensis has shown that cadmium is associated with high molecular weight Cd-binding proteins (72 kDa and 43 kDa). The major cadmium-binding protein 72 kDa is glycoprotein. In experiments we have demonstrated that Cd-binding proteins can be induced when there is cadmium exposure. The results of this study strongly suggest that the far eastern scallop Mizuhopecten yessoensis has a unique and well-developed system for the detoxification of heavy metals and it allows for biochemical systems to be maintained in a relatively stable manner in the presence of heavy metals.  相似文献   

19.
Suspended particulate matter (SPM) patterns in the surface waters of the NW Aegean Sea were studied by (1) determining SPM concentration by water filtration, (2) measuring light transmission, and (3) evaluating satellite images. The SPM signals of the three major rivers discharging into the study area were recorded by all three methods, thereby providing information about the sources, transport pathways, and regional dispersion patterns of the SPM. The filtration of water samples and light transmission measurements were found to be good indicators of SPM concentrations in surface waters. Most of the SPM is composed of terrigenous minerals, thus explaining the correlation between the beam attenuation coefficient and the SPM concentration. A Landsat image obtained for the study period was found to adequately reveal regions with high SPM concentrations. Low concentrations, on the other hand, remain obscured. Received: 3 August 1999 / Revision accepted: 15 March 2000  相似文献   

20.
Embryos of Fundulus heteroclitus in the 4–8 cell stage were exposed nine Hg++ (as mercuric chloride) concentrations from 0 to 100 μg/litre (ppb) for 32 days, 5 days, 2 days and 1 day. All but the chronically (32-day) exposed embryos were allowed to continue development in mercury-free water (20% S) after the exposure period to determine the effect of duration of exposure on three parameters of development. Ninety-six hour survival, total hatching success and per cent incidence of lateral spinal curvature were measured. Only embryos exposed to mercury for a single day showed a significant increase in survival in comparison with embryos exposed for a longer period of time after four days of development. Under all conditions of exposure, survival was reduced at concentrations greater than 40 ppb Hg++. Hatching success of chronically exposed embryos was significantly reduced at concentrations greater than 10 ppb Hg++. Significant increases in total hatchability were effected by reducing the duration of exposure to five days and one day. Of eleutheroembryos emerging following chronic exposure to mercury, increases in the incidence of lateral spinal curvature were noted at all concentrations above 20 ppb Hg++. Significant reductions of this disorder were observed among eleutheroembryos exposed to mercury for 5 days, 2 days or 1 day. Of the three parameters measured, the incidence of lateral spinal curvature and the resulting VH50 value gave a more sensitive evaluation of the embryotoxic effects of Hg++ as mercuric chloride on the estuarine teleost, Fundulus heteroclitus.  相似文献   

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