Pathological effects of sublethal diazinon on the blood,gill, liver and kidney of the freshwater fish Capoeta damascina

Capoeta damascina has a large distribution in the Middle East and is one of the most abundant fishes in inland waters of Iran. Histopathological symptoms of the blood, gill, liver and kidney of C. damascina were investigated over 1, 5 and 9-day exposure to 0 (control), 0.5, 1 and 1.5?mg?L^?1 diazinon. The data were analysed using analysis of variance and non-parametric multivariate analysis of variance. Diazinon concentration was more important than the exposure time on changes of the tissues. Diazinon decreased red blood cell (RBC), white blood cell (WBC), haematocrit (Hct) and haemoglobin (Hb). The symptoms of the gill were mainly desquamation, epithelial hyperplasia, hyperplasia at the base of secondary lamella, epithelial lifting and curling. The prevalent symptoms of the liver were degeneration of nuclei, alternation in size and shape of hepatocytes, focal necrosis and pyknosis. Degeneration of Bowman's capsule, necrosis in renal tubule and haematopoietic tissue were the most common symptoms found in the kidney. In conclusion, the blood, gill, liver and kidney of C. damascina are sensitive enough to respond to low concentrations of diazinon over a short period and this species can thus be a bioindicator of diazinon.     

Toxicity of metals to tadpoles of the common Sunda toad,Duttaphrynus melanostictus

Tadpoles of the common freshwater Sunda toad, Duttaphrynus melanostictus (Amphibia, Bufonidae), were exposed for a 4-day period under laboratory conditions to copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminum (Al), and manganese (Mn) at various concentrations. Mortality was assessed and median times of death (LT₅₀) and lethal concentrations (LC₅₀) were calculated. LT₅₀ and LC₅₀ increased with the decrease in mean exposure times and concentrations for all metals. LC₅₀ (96?h) for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.03, 0.3, 4.2, 1.5, 8.8, 0.4, 1.9, and 39?mg?L^?1, respectively. Cu was the most toxic to D. melanostictus, followed by Cd, Fe, Al, Pb, Zn, Ni, and Mn (Cu?>?Cd?>?Fe?>?Al?>?Pb?>?Zn?>?Ni?>?Mn). Duttaphrynus melanostictus is similarly sensitive to these metals as other amphibian tadpoles.     

Acute hematological toxicity of ivermectin to juvenile Clarias gariepinus

Abstract

Acute behavioral and hematological toxicity of ivermectin to C. gariepinus juveniles were assessed under static conditions at concentrations of 9 to 25?µg L^?1 for up to 4?days. Juveniles were highly sensitive to ivermectin, with an LC50 of 15?µg L^?1, culminating in spasms and paralysis. The hematological responses of packed cell volume, hemoglobin and red blood cell count decreased when compared to the control while the white blood cell count showed a biphasic trend. The mean corpuscular volume and mean corpuscular hemoglobin showed a mixed trend, while mean corpuscular hemoglobin concentration increased with increase in the concentration of the drug. Lymphocytes and neutrophils were also significantly (p?<?.05) increased. Ivermectin did not elicit any significant changes in monocytes, basophils and eosinophils. The observed changes confirm that ivermectin negatively affected the health of the fish. Therefore, real-time monitoring for early warning is recommended.     

Responses of the Indian major carp Labeo rohita to deltamethrin at acute and sublethal concentrations

The effects of deltamethrin at acute and sublethal concentrations on some hematological and biochemical profiles in the Indian major carp Labeo rohita have been examined. The lethal concentrations (LC₅₀) of deltamethrin for 24 and 96 h were found to be 0.44 and 0.38 mg L^?1, respectively. During acute treatment (24 h), hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC), white blood cell (WBC), mean cellular volume (MCV), mean cellular hemoglobin (MCH), and mean cellular hemoglobin concentration (MCHC) values were significantly increased compared to control group. Plasma glucose, protein, cholesterol, albumin, globulin, triglyceride, and glycogen in gill and muscle were significantly decreased. Upon sublethal treatment (0.044 mg L^?1, 10th of 24 h LC₅₀), RBC and the biochemical parameters, except glucose and cholesterol, decreased significantly, while MCV, MCH, and MCHC values increased up to the 28th day and then declined. Cholesterol level was significantly increased throughout the study period. A biphasic response in the levels of Hb, Hct, WBC, and glucose were observed during sublethal treatment.     

Comparative effects of five chelating agents on testicular toxicity in mice induced by acute exposure to cadmium

The aim of this study was to develop new antidotes for cadmium (Cd) since this metal is known to produce mammalian toxicity. N-p-hydroxymethylbenzyl-D-glucamine dithiocarbamate (HBGD), N-benzyl-D-glucamine dithiocarbamate (BGD), diethyldithiocarbamate (DDTC), 2,3-dimercaptopropanol (BAL), and ethylenediamine-tetraacetic acid (EDTA) were studied for their ability to inhibit the adverse effects induced by Cd on mouse testes. The parameters examined included concentrations of Cd, calcium (Ca), iron (Fe), and zinc (Zn) in testes, lipid peroxidation (LPO) levels in testes, lactate dehydrogenase (LDH) activity in serum and reproductive ability of male mice. Mice injected intraperitoneally (ip) with CdCl₂ (2.5?mgCd?kg^?1) after 30?min or 24?h, were then injected ip with chelating agents (400?µmol?kg^?1). Cd increased the concentrations of testicular Ca, Cd, Fe, Zn, and LPO levels as well as the activity of LDH in serum. HBGD and BGD effectively prevented the increase in above indices, and improved the reproductive ability weakened by exposure to Cd. The results suggested that HBGD and BGD are more effective detoxificants in the case of testicular toxicity in mice induced by acute exposure to Cd.     

Histology of Sculpin spp. in East Greenland. II. Histopathology and trace element concentrations

Abstract

For many years, the sculpin has been utilized as a sentinel monitoring species for anthropogenic impacts on the marine environment. To further develop its potential as a screening model body burden of several trace elements, including cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and selenium (Se), were investigated. In addition, histopathology in shorthorn sculpins (Myoxocephalus scorpius; n?=?20) and fourhorn sculpins (Myoxocephalus quadricornis; n?=?10) were examined at three sites around the Scoresby Sound settlement in Central East Greenland. Fourhorn sculpins caught at the most distant site from the settlement, contained significantly higher hepatic Cu and Cd concentrations as well as significantly elevated gill Pb levels compared to the shorthorn sculpins collected at two other sites closer to the settlement. Histological examinations showed that fish with significantly higher concentrations of hepatic Cd and Se exhibited greater nuclear alterations, interstitial hyperplasia/hypertrophy, interstitial mononuclear infiltrations and granulomas. Further, fish with higher Cd and Cu gill tissue levels displayed a significantly higher number of cytoplasmic alterations and lamellar epithelium lifting, hypertrophic and hyperplastic epithelium along with mucus cell hyperplasia. While the presence of liver lesions were not species or sex-specific, the presence of gill lesions decreased in the order female fourhorn sculpins?>?female shorthorn sculpins?>?male fourhorn sculpins?>?male shorthorn sculpins. Hepatic Hg concentrations exceeded known lowest observable effect doses (LOED) for fish (0.1–0.5?μg g^?1 ww) in 27% of fish, while liver Cd residues in 80% exceeded LOED (0.42–1.8?μg g^?1 ww). Based upon these results, data suggest that using the sculpin as a valuable sentinel fish species histopathology may serve as a reliable tool for assessing marine ecosystem exposure to trace metals. However, confounding physiological and ecological factors also need to be considered.     

Low blood lead levels and hemoglobin concentrations in preschool children in China

It is well known that lead (Pb) produces reduced haemoglobin (Hb) levels and risk of anemia when blood lead levels (BPb) are greater than 20?µg?dL^?1. Two recent studies reported an increased risk of anemia in children with BPb between 10–20?µg?dL^?1, but few studies examined the association between Hb levels or risk of anemia and BPb under 10?µg?dL^?1. In the present study this association was examined using data of 140 preschool children from a larger prospective cohort study in China. Data showed that compared to children with BPb <5?µg?dL^?1, children with BPb between 7.5–10?µg?dL^?1 had significantly lower Hb levels, but there were no marked differences for other groups. A linear regression model showed a negative relationship between BPb and Hb levels after controlling for age, gender, height, weight, and iron (Fe) deficiency. This finding, although limited by a small sample size, suggests it may be important to examine Pb-induced hemosynthesis effect at concentrations less than 10?µg?dL^?1.     

Cadmium accumulation characteristics of floricultural plant Cosmos bipinnata*

The artificially high soil cadmium (Cd) concentration screening method was used to screen Cd-hyperaccumulators from floricultural plants. Among the five species of floricultural plants screened, Cosmos bipinnata showed the characteristics of Cd-accumulators. A pot experiment was conducted to further study Cd accumulation characteristics of C. bipinnata. The results showed that the biomass, chlorophyll content, superoxide dismutase activity, peroxidase activity and soluble protein content of C. bipinnata first increased and later decreased with the increase in soil Cd concentration, but the carotenoid content and catalase activity of C. bipinnata reduced. Cd contents in roots, stems, leaves and shoots of C. bipinnata increased with increasing soil Cd concentration. When the soil Cd concentration was 50?mg?kg^?1, the Cd content in shoots was up to 112.62?mg?kg^?1, which was higher than the Cd-hyperaccumulator critical value. The root and shoot bioconcentration factors exceeded 1 in various Cd treatments, but the translocation factors were less than 1. When the soil Cd concentration was 50?mg?kg^?1, the Cd accumulation in shoots achieved the maximum of 224.30?μg plant^?1. Therefore, considering the tolerance and accumulation of Cd, C. bipinnata is a Cd-accumulator that could be used to remediate Cd-contaminated urban soil.     

Heavy metal concentration in soil and woody plants in a quarry

This study determined the concentration of three heavy metals zinc (Zn), lead (Pb), and cadmium (Cd) in soil and in a woody plant species, Milicia excelsa, at Ishiagu quarry, Nigeria. The highest soil concentrations of Zn, Pb, and Cd in soil were obtained at 1?m from the quarry site. In M. excelsa, the highest concentrations of Zn, Pb, and Cd were 3.12–9.1, 3.9–6.01, and 0.51–1.12?mg?kg^?1, respectively. There were significant positive correlations between Cd and Zn (r?=?0.963) and Cd and Pb (r?=?0.974) in plants as well as between Cd and Pb (r?=?9.84) in soil. The level of Cd in soil reflected significant pollution compared to average global concentrations in soils.     

Sublethal effect of the dispersant Goldcrew on selected blood parameters of the African cat-fish Clarias gariepinus

Selected hematological parameters of Clarias gariepinus exposed to sublethal concentrations of the dispersant goldcrew were measured weekly for four consecutive weeks under a static renewal condition in order to simulate possible effects of clean-up operations in the aquatic environment. Hemoglobin (Hb) hematocrit (PCV), red blood cell count (RBCC), white blood cell count (WBCC), and platelet values were 15.40–13.58 g dL^?1, 42.36–36.38%, 5.50–4.09 × 10² L^?1, 6.22–6.62 × 10² L^?1 and 362.87–283.0 × 10⁹, respectively, from week 1 to week 4. Duration of exposure had a marked significance (p < 0.05) on all blood parameters except WBCC. Also, Hb, PCV, RBCC, and platelet had values of 15.80–13.27 g dL^?1, 24.12–35.52%, 5.17–4.0 × 10² L^?1, 5.69–6.85 × 10⁹ L^?1, and 395.25–227.25 × 10, respectively, from control to maximum treatment levels. Exposure concentrations have a significant impact (p < 0.05) on all blood parameters. It may be concluded that Goldcrew has a marked negative effect on fish blood and therefore a need to observe restraint in its usage.     

Acute toxicity of ammonia to a freshwater teleost,Labeo bata larvae

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0?±?4.0?mg) was recorded when exposed to ammonia concentrations of 1.0–13.56?mg?L^?1 at 96?h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25?mg?L^?1 showed 10–74% mortalities. The 96?h LC₅₀ value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5?mg?L^?1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24?h after exposure. A 96?h LC₅₀ value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.     

Soil biological characteristic,nutrient contents and stoichiometry as affected by different types of remediation in a smelter-impacted soil

ABSTRACT

In order to evaluate the ecological risk reductions of copper (Cu) and cadmium (Cd) and the change of nutrient contents and stoichiometry in a smelter-impacted farmland in Guixi, Jiangxi Province, China, with ～ 800?mg Cu kg^?1 soil and 0.8?mg Cd kg^?1 soil, an three years in situ experiment was conducted. The field trial consisted of 4 ×?5?m plots in a completely randomised block design. Hydroxyapatite was added at 10?g kg^?1 soil and Sedum plumbizincicola, Elsholtzia splendens, and Pennisetum sp. were planted. Post-treatment soil and plant samples were collected annually and analysed for Cu and Cd bioaccessibility, soil carbon: nitrogen: phosphorus (C:N:P), and the stoichiometries of soil β-glucosidase (BG), N-acetylglucosaminidase (NAG), and acid phosphatase (AP) activity levels. The results indicated that the hydroxyapatite treatments significantly reduced Cu and Cd bioaccessibility as well as the ratio of C:P and N:P. Moreover, BG, NAG, and AP activity levels all increased relative to those in untreated soil. Plants may also influence soil BG, NAG, and AP activity. This study demonstrated that in situ Cu and Cd stabilisation by hydroxyapatite and phytoextraction is ecologically safe and can alter soil mineral nutrient ecological stoichiometry and enzyme activity.     

Low uptakes of Cd,Cu, and Zn in Dugesia japonica,a freshwater planarian with higher tolerance to metals

Although a freshwater planarian is proposed as a potential model for studying toxicities of environmental pollutants, they are less sensitive to metal exposures, compared to other freshwater invertebrates. We hypothesised that the metal uptake is low in treated planarians, which may lead to their higher tolerance to metals. The acute toxicities of Cu and Zn to Dugesia japonica were determined. The 24- and 48-h median lethal concentrations were 4.50 and 3.46?mg?L^?1, respectively, for Cu, and 41.97 and 37.79?mg?L^?1, respectively, for Zn. Accordingly, combining with the data on Cd in our previous study, higher tolerance of planarians to metals was revealed. Also, tissue levels of Cd, Cu, and Zn in treated D. japonica were determined, and their dissolved uptake rate constants (k₁) were calculated. Results showed that bioaccumulations of these metals in D. japonica were, indeed, lower than that in other freshwater invertebrates having higher susceptibilities to these metals.     

Heavy metals in soils and crops in Southeast Asia

In a reconnaissance soil geochemical and plant survey undertaken to study the heavy metal uptake by major food crops in Malaysia, 241 soils were analysed for cation exchange capacity (CEC), organic carbon (C), pH, electrical conductivity (EC) and available phosphorus (P) using appropriate procedures. These soils were also analysed for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn) using aqua regia digestion, together with 180 plant samples using nitric acid digestion. Regression analysis between the edible plant part and aqua regia soluble soil As, Cd, Cr, Cu, Hg, Ni, Pb and Zn concentrations sampled throughout Peninsular Malaysia, indicated a positive relationship for Pb in all the plants sampled in the survey (R ² = 0.195, p < 0.001), for Ni in corn (R ² = 0.649, p < 0.005), for Cu in chilli (R ² = 0.344, p < 0.010) and for Zn in chilli (R ² = 0.501, p < 0.001). Principal component analysis of the soil data suggested that concentrations of Co, Ni, Pb and Zn were strongly correlated with concentrations of Al and Fe, which is suggestive of evidence of background variations due to changes in soil mineralogy. Thus the evidence for widespread contamination of soils by these elements through agricultural activities is not strong. Chromium was correlated with soil pH and EC, Na, S, and Ca while Hg was not correlated with any of these components, suggesting diffuse pollution by aerial deposition. However As, Cd, Cu were strongly associated with organic matter and available and aqua regia soluble soil P, which we attribute to inputs in agricultural fertilisers and soil organic amendments (e.g. manures, composts).     

Assessment of metals in soil extracts and their uptake and movement within Tamarix nilotica at Lake Nasser banks,Egypt

This study aims to determine heavy-metal levels in soil from the banks of Lake Nasser, the ability of Tamarix nilotica to accumulate such metals from soil and hence its potential for phytoextraction. Soil and Tamarix samples were collected from the banks of four bights around Lake Nasser and analysed for Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. Three different methods of extraction were used for the soil samples. Lead, copper and zinc were equally distributed between the exchangeable phase and Fe/Mn oxide-bound form, while other measured metals were mainly present in the Fe/Mn oxide fraction. With the exception of iron, all metals studied showed total concentrations within the geochemical background values. T. nilotica exhibited elevated concentrations of Na (36.2–48.5?mg?g^?1) and K (2.74–4.33?mg?g^?1) in stems, and relatively high concentrations of Pb, Cd and Co (0.39–1.03?µg?g^?1, 0.24–1.3?µg?g^?1 and 1.94–5.3?µg?g^?1, respectively) are found in plant leaves. Bioaccumulation factors of Na and K (9.3 and 12.63, respectively) were high in T. nilotica stems. While the bioaccumulation of Pb, Cd, Co and Ni (2870.1, 2035.4, 10.5 and 5313.2, respectively) was high in plant leaves, Fe, Mn, Ca and Mg were accumulated relatively equally in plant stems and leaves. T. nilotica was found to secrete high amounts of Na, Ca and K, in addition to small amounts of all accumulated metals except Cd and Cu. These secreted metals appeared as salt crystals (67.5% Na; 25.8% Ca; 5% Mg; 1.5% K and 0.16% trace and minor elements) on the plant surface. The concentrations of all the metals studied in T. nilotica were higher than in the salt crystals. Statistical analysis of the database suggests bioaccumulation of these metals from soil to T. nilotica. This reflects the importance of using T. nilotica as a model in the phytoremediation process as an established environmental clean-up technology.     

Heavy metal pollution in soil and plants at bone char site

This study determined the heavy metal concentration in soil and plants at a bone char site in Umuahia, Nigeria. Soil and plant samples collected in a randomized complete block design (RCBD) were analyzed for zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), and arsenic (As). The concentration of metals in soil and plants in the vicinity of the bone char site are as follows: Zn (172?mg?kg^?1) and Ni (0.62?mg?kg^?1) in soil were highest at site P₃, Pb (2.37?mg?kg^?1) and As (0.08?mg?kg^?1) at site P₁, and Cd (18.30?mg?kg^?1) at site P₂. In plants, the concentrations of Zn (41.17?mg?kg^?1) and Cd (3?mg?kg^?1) were highest in Albizia ferruginea, Ni in Dialium guineense (0.09?mg?kg^?1), while Pb was in D. guineense (0.08?mg?kg^?1) and Spathodea companulata (0.06?mg?kg^?1). The levels of Zn, Cd, Pb, Ni, and As in soil ranged from 11.2 to 172, 2.68 to 18.2, 0.026 to 2.37, 0.33 to 0.62, and 0.02 to 0.08?mg?kg^?1, respectively. In plants, the concentration of Zn, Cd, Pb, and Ni ranged from 2.01 to 41.17, 0.12 to 3, 0.02 to 0.08, and 0.03 to 0.09?mg?kg^?1, respectively. There were significant correlations between Zn and Cd, and Pb and As in soil. The high concentration of Cd in soil might affect soil productivity.     

Effects of Cadmium on Nutrient Uptake and Translocation by Indian Mustard

Plants that hyperaccumulate metals are ideal subjects for studying the mechanisms of metal and mineral nutrient uptake in the plant kingdom. Indian Mustard (Brassica juncea) has been shown to accumulate moderate levels of Cd, Pb, Cr, Ni, Zn, and Cu. In this experiment, 10 levels of Cd concentration treatments were imposed by adding 10–190 mg Cd kg^–1 to the soils as cadmium nitrate [Cd(NO₃)₂]. The effect of Cd on phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and the micronutrients iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in B. juncea was studied. Plant growth was affected negatively by Cd, root biomass decreased significantly at 170 mg Cd kg^–1 dry weight soils treatment. Cadmium accumulation both in shoots and roots increased with increasing soil Cd treatments. The highest concentration of Cd was up to 300 mg kg^–1 d.w. in the roots and 160 mg kg^–1 d.w. in the shoots. The nutrients mainly affected by Cd were P, K, Ca, Fe, and Zn in the roots, and P, K, Ca, and Cu in the shoots. K and P concentrations in roots increased significantly when Cd was added at 170 mg kg^–1, and this was almost the same level at which root growth was inhibited. Zn concentrations in roots decreased significantly when added Cd concentration was increased from 50 to 110 mg kg^–1, then remained constant with Cd treatments from 110 to 190 mg kg^–1. However, Zn concentrations in the shoots seemed less affected by Cd. It is possible that Zn uptake was affected by the Cd but not the translocation of Zn within the plant. Ca and Mg accumulation in roots and shoots showed similar trends. This result indicates that Ca and Mg uptake is a non-specific process.     

镉胁迫对脊尾白虾的毒性效应研究

为揭示重金属镉对脊尾白虾的毒性效应,采用急性毒性实验方法,研究了不同浓度镉(Cd~(2+))对脊尾白虾(Exopalaemon carinicauda)血清氧化应激相关生理指标的活性以及肌肉组织中腺苷酸转移酶基因(ANT)和热激蛋白70基因(HSC70)表达水平的影响。共设置4个Cd2+浓度胁迫(0、0.0002、0.001、0.005 mmol·L~(-1)),分别在0、3、6、9、12、24、36、48、72和96 h共10个时间点对相关指标进行测定。结果显示:不同浓度镉胁迫下,脊尾白虾血清中H_2O_2含量、MDA含量和GSH含量均表现为先升高后降低的趋势,H2O2含量在胁迫3 h时即出现明显的升高,而MDA和GSH则均在9 h时出现升高趋势,表现为一定的滞后性。H2O2含量在0.005 mmol·L~(-1)胁迫3 h时出现峰值,MDA含量在0.005 mmol·L~(-1)胁迫9 h时出现峰值,GSH含量在0.001mmol·L~(-1)胁迫48 h时出现峰值,且均与对照组存在显著性差异(P0.05)。HSC70基因的表达量在不同浓度胁迫下均表现为先升高后降低的趋势,且均在24 h时达到峰值,具体表达量水平的顺序为:0.0002 mmol·L~(-1)0.001 mmol·L~(-1)0.005 mmol·L~(-1)。ANT基因的表达量在不同浓度下则均表现为明显的下调趋势。由此可见,急性Cd~(2+)胁迫不仅影响脊尾白虾的氧化应激相关生理指标,还影响机体内组成型HSC70及与能量传递有关的ANT基因的表达水平。     

Comparative changes in absorption,distribution and toxicity of copper and cadmium chloride in toads during the hibernation and the role of vitamin C against their toxicity

The aim of this study was to determine the bioavailability and adverse effects of cadmium (Cd) and copper (Cu) on hibernating Egyptian toads and whether ascorbic acid (vitamin C) blocked Cd- and Cu-induced effects during hibernation. The oxidative status of liver, kidney, and intestine of Bufo regularis to Cd, Cu, and/or a combination of both metals administered orally for 2 weeks was determined. In the protection studies, vitamin C was given for 1?h prior to administration of Cu, Cd, and/or metal combination for 2 weeks. Treatment with Cu, Cd, and a combination of both metals produced a reduction in red blood count cells and hemoglobin content, while white blood count cells showed an increase in numbers during these treatments. After 2 weeks exposure, Cd and Cu increased significantly in all the tissues studied. Cu storage presented the following sequence: liver?>?intestine?>?kidney. Cd storage presented the following sequence: intestine?>?kidney?>?liver. When exposed to both metals, Cu and Cd storage presented the following sequence: liver?>?intestine?>?kidney. Histopathological examination of the liver revealed marked alterations including loss of hepatic cell architecture, and some cells exhibited distinct cytoplasmic vacuoles. The majority of blood vessels exhibited a marked dilatation and congestion with infiltration of blood cells, prominent hyperemia of hepatic veins, and significant proliferation of bile ductules. Histopathological changes in the kidney showed destruction and degeneration of both renal tubule cells and glomerular with infiltration of leukocytes and inflammatory cells. Histopathological alterations in the intestine were restricted to the innermost mucosal epithelium with marked degeneration of the villi and submucosa and an extensive fragmentation of mucosal epithelium as well as atrophy of goblet cells. The administration of vitamin C 1?h prior to administration of Cd, Cu, and metal combination did not protect against hepatic, renal, and intestinal damage. However, parental vitamin C given alone increased tissue toxicity.     

铜污染草地对放牧乌蒙半细毛羊矿物质元素代谢的影响

为了评价草地铜污染对放牧乌蒙半细毛羊的影响,探讨铜污染的治理方法,在乌蒙山区的妈姑镇和凉水沟开展草地放牧试验和矿物质元素补充研究。应用原子发射光谱分析土壤、牧草和动物组织的重金属含量,应用全自动血液分析仪分析血液指标。放牧试验的结果显示:铜污染草地放牧明显增加了动物组织铜和锌的含量(P 0.01),降低了动物组织钼和铁的含量(P 0.01),试验结束时,试验组动物的血红蛋白(Hb)、红细胞压积(PCV)、红细胞数(RBC)和平均红细胞体积(MCV)显著低于对照组(P 0.01),羊毛产量和长度显著低于对照组(P 0.01)。矿物质元素补充试验的结果显示:补充硫酸钠明显降低了铜污染草地放牧动物血液和肝脏铜元素含量,补充试验结束时,处理Ⅰ组动物血液的Hb、PCV、RBC和MCV显著高于处理Ⅱ组(P 0.01),血液指标达到正常范围。处理Ⅱ组动物血液和肝脏铜元素的含量继续升高,动物组织钼的含量继续降低(P 0.01),Hb、PCV和RBC继续下降,试验结束时出现溶血性贫血,但补充硫对羊毛品质的相关指标没有显著的影响。研究表明,铜污染草地严重影响了乌蒙半细毛羊的矿物质代谢,补充硫酸钠可以部分拮抗铜的毒性。