妊娠期铅暴露对新生仔鼠脑组织MDA、SOD的影响及金属硫蛋白的诱导

目的　探讨妊娠期铅暴露对新生仔鼠脑组织丙二醛 (MDA)、超氧化物歧化酶 (SOD)的影响及对金属硫蛋白 (MT)的诱导。方法　采用灌胃方式于C57小鼠孕第 0d至妊娠结束进行醋酸铅染毒 ,仔鼠出生后第 1d处死 ,取脑组织测定MDA含量及SOD活性 ,同时测定脑组织中MT的含量。结果　妊娠期铅暴露使新生仔鼠脑组织MDA及MT含量升高 ,SOD活性降低 ,均呈明显的剂量 效应关系 (P <0 0 1)。结论　铅的脑发育毒性与其引起脑组织脂质过氧化产物MDA增高及抗氧化酶SOD活性降低有关 ;金属铅可诱导发育中脑组织MT的产生 ,提示MT在体内铅的转运、代谢乃至解毒方面可能具有一定作用     

Effects of heavy metals on production of thiol compounds and antioxidant enzymes in Agaricus bisporus

In a pre-experiment, Agaricus bisporus mycelia grown in PDL medium were found to have a substantial ability to tolerate and accumulate heavy metals. In the study, we investigated changes in the contents of soluble protein and thiol compounds as well as the activities of antioxidant enzymes caused by copper, zinc, lead, and cadmium (nitrate salts) in mycelia of A. bisporus during short-and long-term exposure. Results showed that high-level metal concentrations significantly decrease the contents of soluble protein after long-term exposure, Cu and Zn concentrations significantly increase the thiol compounds levels after long-term exposure, while high-level Cd significantly decrease thiol compounds after long-term exposure. Additionally, SOD activities were significantly increased after long-term exposure to metals, especially to Cd. The CAT activities were enhanced after long-term exposure to low-level Cu and high-level Zn, and enhanced after short-and long-term exposure to high-level Pb. The POD activities were significantly increased after long-term exposure to metals, and increased after short-term exposure to Cd and high-level Pb.     

Impact assessment of various rearing systems on fish health using multibiomarker response and metal accumulation

European sea bass were reared in three different systems: one flow-through (FTS), one recirculating (RAS), and one recirculating with a high-rate algae pond (RAS + HRAP). After 1 year of rearing, the final fish weight was 15% lower in the RAS compared to the FTS. The accumulation of a growth-inhibiting substance in the RAS is the main hypothesis explaining this difference. As in environmental risk assessment, fish bioaccumulation markers and biomarkers were used to demonstrate exposure to and effects of the rearing water in the three rearing systems. Thirty fish per system were sacrificed before their condition factor (CF) and liver somatic index (LSI) were calculated. Nine biomarkers, including ethoxyresorufin-O-deethylase (EROD) and superoxide dismutase (SOD), were measured in liver and twelve metals including As, Cd, Cu, Pb, Cr, and Zn, for which there are regulations regarding human consumption, were measured in liver and muscle. In all systems, CF and LSI were not significantly different and no correlation was found with biomarker activity or metal concentration. EROD and SOD activities were significantly increased in RAS. Accumulation of seven and four metals in muscle and liver, respectively, was significantly higher in the RAS relative to FTS. The HRAP prevented metal accumulation except for chromium and arsenic. Eight metal concentrations were significantly higher in liver than in muscle. Concentrations of toxic metals were similar to reported values and below FAO/WHO recommended values for human consumption.     

Oxidative Stress Parameters,Induction of Lipid Peroxidation,and ATPase Activity in the Liver and Kidney of <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> Exposed to Lead and Mixtures of Lead and Zinc

The purpose of this investigation was to evaluate the effects of lead (Pb) and lead?+?zinc (Zn) combination on the oxidative stress, total ATPase and Pb accumulation in the tissues of Oreochromis niloticus (Linnaeus, 1758). The fish were exposed to 0.1 mg/L Pb (T1), 1.0 mg/L Pb (T2) and mixtures of 0.1 mg/L Pb and 0.5 mg/L Zn (M1); 1.0 mg/L Pb and 5.0 mg/L Zn (M2) for 7 and 21 days. Pb accumulation, total ATPase activity, several antioxidant enzyme activities such as catalase, glutathione peroxidase (GPX), glutathione S-transferase, glutathione reductase, and thiobarbituric acid reactive substances concentrations were measured in the liver and kidney tissues. Metal accumulation in the tissues was higher in Pb exposure compare with mixtures of Pb and Zn exposures. Beside the inhibition of liver GPX activity, general increases of antioxidant enzyme activities in the tissues were recorded after metal exposures. This investigation emphasizes the oxidative stress in O. niloticus caused by Pb, and adaptation of the organisms to the changes in enzyme activities.     

Ecotoxicity of Sediments Contaminated by the Oil Spill Associated with the Tanker “Prestige” Using Juveniles of the Fish Sparus aurata

In November 2002, the oil spill from the tanker Prestige in the Galician Coast caused an ecological catastrophe in Spain. The adverse effects associated with the contaminants bound to sediments were tested using juveniles of the fish Sparus aurata (seabream). The approach evaluates sediment quality by using an integrated assessment including chemical and ecotoxicological data. Sediment samples were physicochemically characterized, and the concentration of contaminants (polycyclic aromatic hydrocarbons—(PAHs) and metals) was measured. Different biomarkers of exposure (metallothioneins and ethoxyresorufin O-deethylase activity (EROD)) and biomarkers of effect (histopathology) were analyzed along the time. A multivariate analysis approach was used to correlate concentration of contaminants and sublethal effects measured in individuals of fish. Results show that increasing concentrations of PAHs in sediments were related to increased EROD activities and histopathological lesions. This is the first evidence showing adverse effects associated with petroleum contamination of PAHs in sediments after this spill, and it demonstrates the utility of the sublethal toxicity tests for monitoring the impact of petroleum spills.     

Concentrations of Metals in Water,Sediment, Biofilm,Benthic Macroinvertebrates,and Fish in the Boulder River Watershed,Montana, and the Role of Colloids in Metal Uptake

To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and Zn in water throughout the watershed exceeded the U.S. EPA acute and chronic criteria for protection of aquatic life. Concentrations of As, Cd, Cu, Pb, and Zn in sediment were sufficient in the tributaries to cause invertebrate toxicity. The concentrations of As, Cu, Cd, Pb, and Zn in invertebrates from lower Cataract Creek (63, 339, 59, 34, and 2,410 μg/g dry wt, respectively) were greater than the concentrations in invertebrates from the Clark Fork River watershed, Montana (19, 174, 2.3, 15, and 648 μg/g, respectively), that were associated with reduced survival, growth, and health of cutthroat trout fed diets composed of those invertebrates. Colloids and biofilm seem to play a critical role in the pathway of metals into the food chain and concentrations of As, Cu, Pb, and Zn in these two components are significantly correlated. We suggest that transfer of metals associated with Fe colloids to biological components of biofilm is an important pathway where metals associated with abiotic components are first available to biotic components. The significant correlations suggest that Cd, Cu, and Zn may move independently to biota (biofilm, invertebrates, or fish tissues) from water and sediment. The possibility exists that Cd, Cu, and Zn concentrations increase in fish tissues as a result of direct contact with water and sediment and indirect exposure through the food chain. However, uptake through the food chain to fish may be more important for As. Although As concentrations in colloids and biofilm were significantly correlated with As water concentrations, As concentrations in fish tissues were not correlated with water. The pathway for Pb into biological components seems to begin with sediment because concentrations of Pb in water were not significantly correlated with any other component and because concentrations of Pb in the water were often below detection limits.     

Combined effects of methylmercury,lead, and cadmium on hepatic metallothionein and metal concentrations in the pekin duck

This study was initiated to determine the effects of combined treatments of methylmercuric chloride (MeHg), lead acetate (Pb) and cadmium chloride (Cd) administered orally on metallothionein (MT) and metal levels in the liver of the pekin duck (Anas platyrynchos). Methylmercury and Pb induced a two-fold increase in MT while Cd caused a seven-fold increase over controls. Concurrent administration of MeHg and Pb caused no increase in MT over single treatments. The hepatic MT content of the MeHg + Cd and MeHg + Pb + Cd groups was not different from the Cdalone group. Hepatic lead levels were lowest followed by Hg and Cd. Lead increased Hg levels when given simultaneously with MeHg, and further addition of Cd increased this effect. In groups given Pb, MeHg increased hepatic levels of this element, but when MeHg was also given with Cd, the combination produced a reduction in levels of Pb. Lead or MeHg had no effect on Cd levels. Methylmercury, Pb, and their combination elevated hepatic Cu over controls. All treatments significantly raised hepatic Zn levels above controls. Combinations of Cd with either MeHg or Pb lowered Zn levels below that caused by Cd alone. The simultaneous administration of all three metals did not produce Zn levels which were additive. The liver content of iron was not significantly altered.     

Effect of Maintaining Rainbow Trout in Creosote Microcosms on Lens Optical Properties and Liver 7-Ethoxyresorufin-O-Deethylase (EROD) Activity

Previously, exposure of fish to polycyclic aromatic hydrocarbons (PAHs) in both field and laboratory settings has been associated with eye damage, but this has only been expressed qualitatively. In this study, an automated scanning laser system has been employed to quantitatively evaluate changes in lens optical quality in rainbow trout (Oncorhynchus mykiss) following their in vivo exposure to creosote, which is a complex mixture with many PAHs. Rainbow trout were placed in 12,000-L outdoor microcosms dosed with 0, 3, or 10 μl/L liquid creosote for a 28-day period. Collected fish were examined for changes in focal length variability (FLV), lens size, and weight. These measurements were compared with induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity and hepatic and water concentrations of priority pollutant PAHs. The optical quality of rainbow trout lenses was significantly reduced following creosote exposure, as indicated by increased FLV. Lens damage was significantly related to hepatic EROD activity, and both effects rose with creosote dose. Analytical measurements of microcosm water indicated elevated concentrations of PAHs in creosote-dosed ponds, including compounds capable of inducing rainbow trout EROD activity in vitro. Hepatic concentrations of PAHs were low and not related to creosote dose, likely due to rapid metabolism and elimination. This study demonstrates for the first time employment of a highly sensitive and quantitative technique to measure lens damage in fish exposed to contaminants in situ. The relationship between this effect and hepatic CYP1A activity may suggest a mechanistic linkage, which could lead to the use of EROD activity as an indicator of toxic effect rather than just chemical exposure. Received: 17 May 1999/Accepted: 24 September 1999     

A biomarker approach to measure biological effects of contaminant exposure in largemouth bass from Lake Conestee, South Carolina, U.S.A

Sediments from Lake Conestee, a former reservoir now filled with pollutant-enriched sediments, located south of Greenville, South Carolina, USA, and other nearby reservoirs were collected and analyzed for lead and polycyclic aromatic hydrocarbons (PAHs). Hepatic ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were measured in largemouth bass (Micropterus salmoides) to characterize biological effects of these contaminants over three seasons. Results showed that total PAH concentrations in Lake Conestee sediments were significantly greater than the control during each season. An average 10-fold induction in EROD activity was observed at Lake Conestee compared with the control over all three seasons, indicating that PAHs present in sediment were bioavailable to fish. Significant gender effects were observed in EROD activity during the spring, in which activity in reproductively active female fish was significantly suppressed compared with the male fish. Sediments from Lake Conestee had elevated lead concentrations, but the lack of ALAD inhibition in bass indicated that lead was not biologically available. Total GST activity, UGT activity, and SULT activity were not significantly induced in fish from any of the affected sites compared with the reference site. Both EROD and UGT activities were highest during the winter, as were sediment PAH concentrations in Lake Conestee, possibly linked to seasonal resuspension events. The biomarkers measured in this study were useful as a first investigation into the biological effects of contaminant exposure, as well as in determining the bioavailability of contaminants in Lake Conestee.     

Lack of a distinct gradient in biomarker responses in small mammals collected at different distances from a highway

This study describes biomarker effects in small mammals exposed to traffic emissions. Animals were collected at 10–50 m (site 1), 150–200 m (site 2), and 5 km (site 3) from a very busy highway (A2). To distinguish between routes of exposure, strictly carnivorous common shrews (Sorex araneus) and predominantly herbivorous bank voles (Clethrionomys glareolus) were collected. As a measure of exposure to polycyclic aromatic hydrocarbons (PAHs), aromatic DNA adduct levels were determined by ³²P-postlabeling techniques in tissue from heart, lung, and liver. Lead (Pb), cadmium (Cd), and copper (Cu) levels were analyzed in kidney as a measure of exposure to heavy metals. EROD and PROD activity and retinoid levels were determined in liver as effect biomarkers for exposure to PAHs and polyhalogenated aromatic hydrocarbons (PHAHs). Relatively high Cd levels in S. araneus and in particular elevated DNA adduct levels in C. glareolus indicated that small mammals at site 3 were exposed to more compounds than at sites 1 and 2 (3 ≥ 1 > 2). The latter effect is probably due to an incidental and actual input of airborne pollutants that is deposited on plant surfaces. By consumption of above-ground vegetation, voles are chronically exposed to this pollution. Relatively high background input of PAHs probably hinders that the traffic-related gradient of airborne PAH concentrations found in an earlier study is reflected in DNA adduct levels in small mammals in the present study. Moreover, historical biomarkers for exposure to traffic emissions, such as increased kidney Pb levels, increased hepatic EROD activity, and disturbed hepatic vitamin A homeostasis are no longer applicable to indicate differences in exposure. This is a result of the ban on addition of Pb and chlorinated scavengers to gasoline and of cleaner combustion techniques, which were enforced by law over the past decade. Finally, it is advisable to use only juvenile small mammals for in situ monitoring of diffuse pollution because DNA adduct levels increased with age. Received: 5 November 2001/Accepted: 11 March 2002     

Effect of Chronic Sublethal Exposure of Major Heavy Metals on Filtration Rate, Sex Ratio, and Gonad Development of a Bivalve Species

The chronic toxic effects of major heavy metals including copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) on the filtration rate (FR), sex ratio, and gonad development of immature blood clams, Tegillarca granosa, were investigated. The FRs were significantly inhibited by Cu, Pb and Cd, with rates generally decreasing with both increasing metal concentrations and exposure time. EC₅₀ values for FR after 28 days of exposure were 12.9, 12.7 and 14.4 μg/L for Cu, Pb and Cd, respectively. Zn exposure had no effect on FR. Sex ratios were significantly altered from controls in favor of an increased proportion of males at metal concentrations of ≥14.2, ≥86 and ≥110 μg/L for Cu, Pb and Cd, respectively; and at ≥1.68 mg/L for Zn. The gonado-somatic index was significantly reduced in clams at all metal exposures, except for the lowest concentration of Cu (7.1 μg/L).     

Inhibitory effects of heavy metals on cytochrome P4501A induction in permanent fish hepatoma cells

The interactions in vitro of heavy metals Cd(II), Co(II), Cu(II), Ni(II), Pb(II), and Zn(II) with cytochrome P4501A (CYP1A) induction response and enzyme activity were studied in fish hepatoma cells PLHC-1. Cells were simultaneously exposed to heavy metals and to 3-methylcholanthrene (3-MC), an inducer of CYP1A. Heavy metals were added to the cells in different concentrations. Cytotoxicity were measured in the neutral red (NR) assay, relative CYP1A protein contents in an enzyme-linked immunosorbent assay (ELISA), and CYP1A activities in the ethoxyresorufin-O-deethylase (EROD) assay. All metals had a more pronounced effect on EROD activity than on CYP1A protein content and cytotoxicity. For the most active metal Cd(II), a 50% inhibition of EROD activity was observed at significantly lower concentrations (2.2 · 10^–5 M) than a 50% reduction of CYP1A protein (5.3 · 10^–5 M), and a 50% cytotoxicity (1.4 · 10^–4 M). The inhibitory potency of the metals had the following order: Cd(II)>Ni(II)>Cu(II)>Co(II)=Zn(II)>Pb(II). In a second set of experiments, lysates of 3-MC—induced cells were exposed to heavy metals. Cd(II) and Cu(II) caused a 50% inhibition of EROD activity at significantly lower concentrations than in the experiments with living cells, at 8.2 · 10^–6 M and 1.3 · 10^–5 M, respectively, whereas the effect by Co(II) occurred at a significantly higher concentration (8.2 · 10^–4 M). The results indicate that Cd(II) and Cu(II) in particular may affect the CYP1A system of the liver of fish at low concentrations through direct inhibition of the CYP1A enzyme activity. CYP1A induction response in fish liver is increasingly being used in biomonitoring programs. In the environment, interactions of CYP1A-inducing and CYP1A-inhibiting components (such as heavy metals) can be expected and must be taken into consideration.     

Evaluation of Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) in <Emphasis Type="Italic">Mullus barbatus</Emphasis> from Sicily Channel and Risk-Based Consumption Limits

Our study is a preliminary step to evaluate water contamination of the Mediterranean Sea surrounding Lampedusa island and health risks for fish consumers. We analyzed muscle tissue of Mullus barbatus specimens to detect metals and polycyclic aromatic hydrocarbons (PAHs). Results show the following average concentrations of heavy metals: Pb 0.035, Cd 0.001, Hg 0.027, Cr 0.524, As 27.01, Cu 0.433, Co 0.013, Ni 0.042, Se 0.487, V 0.072, U 0.055 and Zn 3.360 ppm. PAHs ranged from 0.250 to 13.16 ppb. A possible risk to human health was determined based on consumption limits data and the content of total PAHs in fillets of this species.     

The influence of water temperature on induced liver EROD activity in Atlantic cod (Gadus morhua) exposed to crude oil and oil dispersants

Juvenile Atlantic cod were exposed to either the water-accommodated fraction (WAF) or the chemically enhanced water-accommodated fraction (CEWAF) of Mediterranean South American (MESA), a medium grade crude oil at three different temperatures. Two concentrations of each mixture were tested, 0.2% and 1.0% (v/v) at 2, 7 and 10 °C. Corexit 9500 was the chemical dispersant tested. The liver enzyme ethoxyresorufin-O-deethylase (EROD) was measured during a 72-h exposure. The WAF of oil had significant (P<0.05) effect on enzyme activity compared to controls at only one sampling time: 48 h at 10 °C. Exposure of CEWAF of oil resulted in significantly (P<0.05) elevated EROD activity compared to controls. The level of EROD induction was temperature related with higher induction being observed in cod exposed to CEWAF at higher temperatures. Total polycyclic aromatic hydrocarbon (PAH) concentrations in exposure water were significantly higher in chemically dispersed mixtures. While PAH concentrations were lower in the 2 °C water compared to 7 or 10 °C (8.7 vs 11.9 μg mL⁻¹), the level of EROD induction was approximately 9 and 12 times lower at 2 °C compared to 7 or 10 °C, respectively, suggesting the metabolic rate of the cod plays a role in the enzyme response. These data suggest the risk of negative impacts associated with exposure to chemically dispersed oil may be affected by water temperature and that risk assessment of potential effects of WAF or CEWAF should consider the effects of water temperature on the physiology of the fish as well as the effectiveness of dispersants.     

Correlation of MT Levels in Livers and Gills with Heavy Metals in Wild Tilapia (Oreochromis mossambicus) from the Klang River,Malaysia

Metallothionein (MT) concentrations in gill and liver tissues of Oreochromis mossambicus were determined to assess biological response of fish to levels of some metals. Metal concentrations in gill and liver tissues of O. mossambicus ranged from 0.6 to 2.6 for Cd, 16 to 52 for Zn, 0.5 to 17 for Cu and 2 to 67 for T–Hg (all in μg/g wet weight, except for T–Hg in ng/g wet weight). Accumulation of Cd, Zn, Cu and Hg (μg/g wet weight) in the liver and gills of O. mossambicus were in the order of liver > gills. The concentrations of Cd, Zn, Cu and Hg in fish tissues were correlated with MT content. The increases in MT levels from the reference area Puchong Tengah compared to the polluted area Kampung Seri Kenangan were 3.4- and 3.8-fold for gills and livers, respectively. The results indicate that MT concentrations were tissue-specific, with the highest levels in the liver. Therefore, the liver can act as a tissue indicator in O. mossambicus in the study area.     

Alleviating Effects of Black Soybean Peptide on Oxidative Stress Injury Induced by Lead in PC12 Cells via Keap1/Nrf2/TXNIP Signaling Pathway

Many researchers have found that Pb exposure can cause oxidative stress damage to the body’s tissue. Black soybean peptide (BSP) has a variety of physiological functions, especially in terms of oxidative stress. Nevertheless, the mitigation function of BSPs on Pb-induced oxidative stress damage in PC12 cells has not been clearly defined. In this study, cell viability was detected by CCK8. Oxidative stress indicators, such as ROS, GSH/GSSG, MDA, SOD, CAT, GPx, and GR, were tested with biochemical kit. Protein expression of Keap1, Nrf2, and TXNIP was measured by Western blot. Compared with the control group, Pb reduced the cell viability of PC12 cells. However, BSP treatment significantly increased the viability of PC12 cells induced by lead exposure (p < 0.05). Lead can enrich the contents of MDA and ROS, but decrease the amount of CAT, SOD, GR, GPx, and GSH/GSSG in PC12 cells, while BSP can alleviate it (p < 0.05). Lead can enhance the expression of Keap1 and TXNIP proteins, but reduce Nrf2 expression. In contrast, BSPs reversed this phenomenon (p < 0.05). BSPs can alleviate oxidative stress injury induced by lead in PC12 cells through the Keap1/Nrf2/TXNIP signaling pathway.     

Assimilation and bioconcentration of Ag and Cd by the marine black bream after waterborne and dietary metal exposure

We determined the aqueous uptake and dietary assimilation of Cd and Ag by the marine black bream Acanthopagrus schlegeli following one to four weeks' exposure (or conditioning) to waterborne or dietary Cd or Ag at different concentrations. The concentrations of metals and metallothioneins (MT) in different tissues also were determined. The viscera contained the highest Ag, Cd, and MT concentrations after metal exposure. After exposure to waterborne metals, the metal and MT concentrations in the gills were higher than those in the remaining tissues (mainly muscles and bones), but this pattern was reversed following exposure to dietary metals. The assimilation efficiencies (AEs) of Cd and Ag ranged from 6 to 24% and 15 to 30%, respectively. The rate constant of uptake from the dissolved phase (ku) of Cd and Ag ranged from 2.2 to 7.5 and 8.0 to 31.7 L kg(-1) d(-l), respectively. In all the exposure experiments, the ku and AE increased with induced MT concentration and tissue metal concentration. Increasing metal accumulation may have been due to the increased available binding sites following the induction of MT in the fish. Furthermore, the MT induced by either Cd or Ag was not specific, but was able to bind with both metals and enhance bioaccumulation. Exposure to dissolved and dietary metals may increase metal accumulation, which potentially may lead to metal toxicity, although the fish may develop a tolerance to metals due to the apparent induction of MT.     

Metal Distribution in the Tissues of Two Benthic Fish from Paddy Fields in the Middle Reach of the Yangtze River

Metal content was determined in two fish species (Misgurnus anguillicaudatus and Monopterus albus) inhabiting rice paddies along the Middle Reach of the Yangtze River. Both are species important food fish in East Asia. The levels of eight metals (Fe, Mn, Zn, Cu, Cr, As, Cd, Pb) in skin, muscle and intestinal tissues were measured and correlated with fish size. Metal distribution among the tissues was examined and the potential risk of fish consumption was evaluated. Correlations between metal concentration and fish size were not significant. Concentrations of essential metals varied significantly among tissues, but the differences were not significant for non-essential metals. Correlations among metals in skin tissue were stronger than in intestinal and muscle tissues. Metal concentrations in the edible tissues of both fish met permissible levels for consumption, except Pb in loach skin and Cr loach in muscle. The potential risk caused by Pb from skin and Cr from muscle of loach consumption should be considered in future risk assessmeents.     

Effect of lead on ALA-D activity,metallothionein levels,and lipid peroxidation in blood,kidney, and liver of the toadfish Halobatrachus didactylus

The effects of lead (Pb) on ALA-D activity, metallothionein (MT) levels, and lipid peroxidation in liver, kidney, and blood of the toadfish Halobatrachus didactylus were investigated. A time-course experiment was performed with sampling on days 0, 2, 5, and 7 following intraperitoneal Pb injection. This indicated a rank order for lead concentration of kidney > liver > blood in fish exposed to Pb. No significant variation of ALA-D activity was observed in liver and kidney while in blood, a slight decrease of ALA-D activity was found but this was not attributed to acute metal stress. Hepatic and renal MT levels were both affected in different ways by metal uptake. The progressive decrease of MDA concentration in the liver and the lack of a clear induction in kidney suggested the hypothesis that Pb is not a good inductor of lipid peroxidation. The histological and histochemical results demonstrated degenerative effects of lead accumulation on the tissues and the activation of lysosomal responses to induced stress.     

Participation of metallothionein and superoxide dismutase in the blood of smoking smelters

Objectives

Metallothionein (MT) and two forms of superoxide dismutase (SOD), which are dependent on zinc and copper ions, are involved in defense against the same superoxide anion radicals and are present in extra- and intracellular compartments. The aim of our study was to investigate MT concentration and Cu/Zn SOD activity in the plasma and erythrocyte lysate of the non-smoking and smoking smelters.

Material and Methods

The investigations were performed in the blood of 300 male smelters and 100 non-exposed male subjects. We have measured zinc, copper, malondialdehyde (MDA) and MT concentrations as well as SOD activity.

Results

We have observed an increase of Cu/Zn coefficient and decrease of Zn/Cu coefficient in the serum of smelters in comparison with the non-smoking control group. Concentration of MDA in the plasma of smelters was higher in comparison with its concentration in the non-smoking control group. The plasma and the erythrocyte lysate MT concentration increased significantly in the whole group of smelters as compared to the non-smoking control group. The mean value of MT concentration in plasma of the smoking smelters was above 2-fold higher than in the non-smoking control group. The activity of Cu/Zn SOD in plasma of the smoking and non-smoking smelters was decreased in comparison with the smoking and non-smoking control groups, respectively. The lowest activity of Cu/Zn SOD, about 2–3-fold decreased in comparison with the smoking and non-smoking control groups, was detected in plasma of the smelters. An inverse relationship was observed in the erythrocyte lysate. The highest activity of Cu/Zn SOD was reported in the erythrocyte lysate of the smoking smelters and it was about 2-fold higher than in the non-smoking control group.

Conclusions

In extracellular environment MT plays a crucial role in comparison with the SOD, while in the intracellular compartment Cu/Zn SOD and MT cooperate with each other.