Cd Concentrations In Liver Research Articles

Contrasting trophic transfer patterns of cadmium and mercury in the Arctic marine food web of east Hudson Bay, Canada

We investigated trophic transfer of cadmium (Cd) through an Arctic marine food web in Hudson Bay and compared it with mercury (Hg), a metal known to strongly biomagnify. We evaluated blue mussel, sea urchin, common eider, sculpin, Arctic cod, and ringed seal for the influence of dietary and biological variables on variation in Cd and Hg concentrations. Age and size influenced metal concentrations among individuals within a vertebrate species. Consumer carbon and sulfur isotope values were correlated with their Cd and Hg concentrations, indicating habitat-specific feeding influenced metal bioaccumulation. Trophic transfer patterns for Cd depended on the vertebrate tissue, with food web biodilution observed for the muscle but not the liver. Liver Cd concentrations were higher in ringed seal and some common eider relative to prey. In contrast, we observed mercury biomagnification for both tissues. Tissue- and species-specific physiology can explain discrepancies of Cd trophic transfer in this Arctic marine food web.

Coral fossil: A potential adsorbent of natural source for cadmium removal in broilers

Cadmium (Cd) is a pollutant that poses a health risk for humans and animals. Coral fossil (CF) acts as an adsorbent, yet limited knowledge is available on impacts of CF on Cd toxicities. The work was performed to figure out the effects of CF on hematobiochemical details and specific organs in Cd exposed broilers. The experiment was carried out with 45 broilers and were divided into three groups (15 in each). Group A was served as control. The birds in group B received Cd (75 mg /kg b. w.) orally. Whereas group C was orally supplemented with Cd (75 mg /kg b. w.) and CF (1 gm/kg b. w.). The trial was lasted for 30 days. For hematobiochemical analysis, blood samples were drawn, and sera were separated. Liver, kidney and muscle were collected to assess accumulation concentration. Brain, liver and kidney samples were also collected for histopathological study. The results showed that hematological parameters (TEC, Hb, PCV, MCV, MCH, MCHC and DLC) were altered by Cd but restored with CF supplementation. Liver (AST, ALT and ALP) and kidney (total protein and creatinine) biomarkers were increased significantly in Cd treated broilers while decreased significantly after CF supplementation. CF reduced accumulation concentration of Cd in liver, kidney and muscle. Cd intoxicated broilers showed degenerative changes in brain, hyperplastic bile duct and proliferation of renal tubular epithelium with focal degeneration and necrosis; and these were improved after CF supplementation. Therefore, it can be concluded that CF is a potential adsorbent against Cd toxicities.

CONTENIDO DE PLOMO, CADMIO Y ARSÉNICO EN TEJIDOS BIOLÓGICOS DE LA PALOMA COMÚN (Columba livia) PRESENTES EN UN ÁREA URBANA PREVIAMENTE CONTAMINADA CON RESIDUOS MINEROS

The north of Chile presents numerous cases of environmental contamination by heavy metals and others chemical elements, particularly due to the inadequate handling of its waste. In the Arica city, northern Chile, in the decade of 1980, 19 000 tons of mining waste were deposited from Europe, with high contents of Pb, As and Cd. Its effects have only been evaluated in the human population, but until now it is unknown if those chemical elements were incorporated by other species that are part of the biological community of the urban radius. In this study we evaluated the presence and concentrations of Pb, As and Cd in feral pigeons ( Columba livia ) inhabitants of Arica, both in the urban radius and in a nearby valley (valley of Azapa). The values found are higher in relation to other birds of similar ecological characteristics. For example, regarding Pb, 1.7 μg/g were found on average in liver tissue and 10.84 μg/g in bone tissue. In relation to As, concentrations were 2.63 μg/g in liver tissue and 2.13 μg/g in bone. Finally, concentrations of Cd in liver were 11.7 μg/g and 3.43 μg/g in bones. This indicates that the common pigeons from Arica are highly contaminated by heavy metals and arsenic and could be considered an environmental bioindicator species for future environmental assessment of the city.

Influence of ferulic acid consumption in ameliorating the cadmium-induced liver and renal oxidative damage in rats.

The aim of this study relates to the modulatory role of ferulic acid (FA) against cadmium (Cd)-induced oxidative stress in the liver and kidney of male Wistar albino rats. Cd is an extremely toxic industrial and environmental pollutant and is well known for its varied toxic clinical manifestations. FA is a derivative of curcumin and a ubiquitous phenolic compound having a wide range of therapeutic activities. In the current study, Cd (10mg/kg) was administered subcutaneously for 15 and 30days to induce hepato-renal toxicity. Cd concentration was found to be significantly high in Cd-intoxicated rats (liver > kidney) while the supplementation of FA (50mg/kg) significantly reduces the Cd concentration in liver and kidney tissues. Reduced body and organ weights and food and water consumption and increased rectal temperature were noticed in Cd-treated rats while these parameters were significantly ameliorated in FA-supplemented rats. Liver and kidney damage induced by Cd was significantly revealed by the reduction in serum total protein contents (TPC) and increased activities of serum nitric oxide (NO) levels and hepato-nephrotoxicity marker enzymes, namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), AST:ALT ratio, uric acid, urea, urea nitrogen, and creatinine, along with the increased levels of hepatic and renal oxidative stress markers, namely lipid peroxidation (MDA levels), lipid hydroperoxides (LOOH), protein carbonyl content (PCC), total oxidant status (TOS), and oxidative stress index (OSI) in liver and kidney tissues. In addition, the toxicity of Cd was also evidenced by a significant decrease in the levels of total thiols (TTH), total antioxidant concentration (TAC), enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)), and non-enzymatic antioxidants (reduced glutathione (GSH) and total free sulfhydryl groups (TSH)). Administration of FA significantly restored the serum total protein levels and activities of serum NO levels and hepatic and renal marker enzymes to normal levels in comparison with Cd-intoxicated rats. Furthermore, FA significantly reduced the oxidative stress markers and recuperated the levels of antioxidant defense in the liver and kidney as evidenced by native PAGE and spectrophotometric assays, correlation and regression analysis and multivariate analysis of variance (MANOVA), and inferring the antioxidant role of FA. Histopathological damage due to Cd intoxication in the liver and kidney is demonstrated as vasodilatation and congestion in central veins and sinusoids as well as around the glomerulus, infiltration of mixed inflammatory cells and peripheral hemorrhage, hemorrhagic and enlarged sinusoids, disorganization of the hepatic parenchyma, focal necrosis, swelling of hepatocytes, calcified tissue inside blood vessels, hepatocyte degeneration and vacuolization of liver cells, hyaline casts, degenerated glomerulus with wide space and detached basement membrane, distal tubule with wide lumen, deformed proximal tubules with detached brush border, and degeneration and hyalinization of glomerular tuft. But, FA significantly reduced the toxicity of Cd and protected the normal histological architecture of the liver and kidney tissues. Cd-intoxicated rats were associated with a significant upregulation of TNF-α, COX-2, and HSP70 proteins, whereas treatment with FA caused downregulation of the above inflammatory markers indicating the anti-inflammatory role of FA. Principal component analysis (PCA) and Euclidean similarity measure studies clearly indicate that the liver is more prone to Cd toxicity than the kidney and FA supplementation significantly prevents oxidative stress, augmenting antioxidative status, and regaining histological parameters of the liver and kidney to normal, indicating hepato-nephroprotective, antiradical, antioxidant, and anti-inflammatory effects of this phenolic compound.

PESTICIDES AND TOXIC METALS RESIDUES IN MUSCLE AND LIVER TISSUES OF SHEEP, CATTLE AND DROMEDARY CAMEL IN SAUDI ARABIA

Data regarding determination of pesticide residues and toxic elements in edible tissues of different animals particularly in the camels in Eastern region of Saudi Arabia are scarce. Therefore, current study aimed to evaluate levels of forty-five pesticides and heavy metals (lead (Pb); cadmium (Cd); Arsenic (As)) in muscle and liver tissue samples that collected from forty-two animals; sheep (n=21), cattle (n=11) and dromedary camels (n=10) admitted to Al-Ahsa abattoir, Eastern province, Saudi Arabia. Seven of forty-five pesticides residues were detected in tissues by gas chromatographic mass spectrometry (GC/MS). The detected pesticides were organophosphorus (diazinon, profenofos and coumaphos), pyrethroid (cypermethrin, permethrin and lambda-cyhalothrin) and acaricide (amitraz). Diazinon has been detected in both muscle and liver tissues of all examined carcasses. However, other detected residues distributed according to species. All toxic metals have been detected in both muscle and liver tissues of all tested animals. The heavy metal loads were species independent. The concentrations of Pb and As in liver tissues were comparable to that of muscle tissues of all tested animals. However, the concentrations of Cd in liver were significantly higher than that in muscles of all tested animals. All values of detected pesticide residues and heavy metals were below the maximum residue limits (MRLs). In conclusion, pesticide residues and toxic metals were detected in meat and liver tissues of sheep, cattle and dromedary camels that admitted to Al-Ahsa abattoir, Saudi Arabia. The detected pesticides residues and toxic metals were well below MRLs; thereby no risks are associated with its human consumption.Key words: chromatography; residues; toxic elements; meat; pesticides; animals

Transcriptomic analysis on responses of the liver and kidney of finishing pigs fed cadmium contaminated rice.

Cadmium (Cd) is a common harmful substance that has many deleterious effects on the liver and kidney. Most reports about Cd toxic studies focused on its inorganic status, whereas the toxicity of Cd in organic materials is less studied. Here, we performed RNA-seq to explore the influences of Cd contaminated rice on function of the liver and kidney of finishing pigs. The concentration of Cd in liver and kidney of pigs fed Cd contaminated rice increased by 4.00 and 2.94 times, respectively, compared to those in the control group. With transcriptomic analysis, approximately 4-6 × 107 clean reads were acquired. Five differently expressed genes (DEGs) were identified in the liver, and 12 DEGs in the kidney. SPHK2 was commonly down-regulated. No significantly enriched gene ontology (GO) terms were identified. By Kyoto encyclopaedia of genes and genomes (KEGG) enrichments, four pathways were identified in hepatic tissue, and five pathways in nephritic tissue. Intriguingly, two pathways (sphingolipid metabolism and VEGF signalling pathway) were altered both in the liver and kidney. Cd contaminated rice may cause liver and kidney damage and inflammation, or even lead to more severe harm to these tissues. © 2017 Society of Chemical Industry.

English

Previous studies revealed high levels of metals in soils, drinking water, foodstuffs and food animals in several communities in Tarkwa, Ghana. Therefore wild rats were trapped from 16 communities in Tarkwa to estimate the environmental pollution state of metals; determine differences in sex in metal accumulation; and assess the potential risks involved. Concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) were measured in the livers and kidneys of wild rats; and livers accumulated higher levels of As than kidneys but the reverse was for Cd and Pb. In both organs, As, Cd and Zn levels were higher in female than the male rats. There was a strong positive correlation between body weight and Cd concentrations in livers and kidneys of wild rats which reflects a mechanism of protection against the development of osteopenia, although a biological effect remains a concern. Pb levels in the kidneys could cause intra nuclear inclusion bodies and karyocytomegaly in the proximal tubular cells in 29% of wild rats in Tarkwa and structural and functional kidney damage in 6%. Concentrations of As in kidneys of these wild rats could cause glomerular swelling in 9% of rats. Principal component analysis of the results showed that wild rats in Tarkwa were exposed to heavy metals and a metalloid through borehole drinking water and soils. Key words: Wild rats, heavy metal, metalloid, liver, kidney, Ghana.

Alleviation effect of dietary cerium and its complex with chitosan oligosaccharide on cadmium accumulation in juvenile turbot,Scophthalmus maximusL., under cadmium stress

An 8 weeks feeding trial was conducted to investigate the effect of dietary cerium (Ce) and its complex with chitosan oligosaccharide (COS-Ce) on growth performance and cadmium (Cd) accumulation of turbot, Scophthalmus maximus L. under Cd stress. The basal diet (Diet 0) was formulated without Cd and cerium as the control. Seven other experimental diets (Diets 1–7) were formulated with supplementation of 50 mg Cd2+/kg feed, 50 mg Cd2+/kg and 50 mg Ce3+/kg feed, 50 mg Cd2+/kg and 100 mg Ce3+/kg feed, 50 mg Cd2+/kg and 200 mg Ce3+/kg feed, 50 mg Cd2+/kg and 50 mg COS-Ce/kg feed, 50 mg Cd2+/kg and 100 mg COS-Ce/kg feed, and 50 mg Cd2+/kg +200 mg COS-Ce/kg feed. Results of the present study showed that, compared with the control group, the condition factor in fish fed the diet with 50 mg Cd2+/kg feed (Diet 1) was significantly lower, whereas the Cd concentration in liver and kidney of fish fed the diet with 50 mg/kg Cd2+ (Diet 1) was significantly higher (P < 0.05). The high Cd accumulation of fish fed diets with sole 50 mg/kg Cd (Diet 1) could be significantly decreased by 51.72% after supplementation of 200 mg COS-Ce/kg in the diet (Diet 7). These results suggested that elevated COS-Ce could effectively protect against dietary Cd accumulation in turbot.

Concentration of heavy metals (Pb, Cd) in muscle and liver of Perca fluviatilis and Tinca tinca in Anzali Wetland, southwest the Caspian Sea

Anzali Wetland is one of the most important aquatic ecosystems of Iran located at southwest of the Caspian Sea. This wetland is a habitat for valuable fish with vital role in life cycle of this ecosystem. Assessment of pollutants concentration is rational due to complications of determining biological effects in a habitat. The present study examined the concentration of lead (Pb) and cadmium (Cd) in muscles and livers of two fish species i.e. Perca fluviatilis and Tinca tinca collected from Anzali Wetland, and their relationships with fish size (length and weight). The results showed the highest concentration of metals in liver, and the lowest in muscle tissues of both species. Highest concentrations of Cd (0.09) and Pb (3.66) were recorded in liver tissue of T. tinca . The results also showed significant negative correlation between metal concentrations and fish size. Highly significant (P<0.01) negative relationships were observed between fish length and Pb concentrations in liver of P. fluviatilis . Cd and Pb concentrations in liver of P. fluviatilis and Cd concentrations in the liver of T. tinca showed significant negative relationships (P<0.05) with size factors. The concentrations of Pb and Cd were lower than the maximum acceptable concentrations for fish proposed by MAFF thus safe for human utilization.

Beavers indicate metal pollution away from industrial centers in northeastern Poland.

Heavy metals are persistent environmental contaminants, and wild animals are increasingly exposed to the harmful effects of compounds of anthropogenic origin, even in areas distant from industrial centers. We used atomic absorption spectrometry to determine levels of cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn) in liver and kidney of wild Eurasian beavers (Castor fiber) in Poland. Cd concentrations in liver (0.21 ± 0.44 μg/g) and in kidney (2.81 ± 4.52 μg/g) were lower in juvenile than in adult beavers. Pb concentrations in liver (0.08 ± 0.03 μg/g) and kidney (0.08 ± 0.03 μg/g) were similar among all individuals, while both Cu and Zn levels were higher in liver (Cu 9.2 ± 4.5 μg/g; Zn 35.7 ± 3.5 μg/g) than in kidney (Cu 3.7 ± 1.1 μg/g; Zn 21.5 ± 2.7 μg/g). Cu levels also differed between juveniles and adults. We reviewed the literature reporting metal concentrations in beavers. Our results indicate metal contamination in beavers away from important industrial emission sources and suggest the natural environment should be regularly monitored to ensure their levels are below recommended, legal values.

The role of metallothionein and metal transporter on cadmium transport from mother to fetus

We examined the role of Metallothionein (MT) and metal transporter on Cadmium (Cd) transport from mother to fetus. In this study, female Wistar rats were given Cd (as CdCl2) at a dose of 0, 1, 2 and 5 mg Cd/kg/d. Animals were sacrificed on the pregnant 19-21 d. The concentrations of Cd and MT, and gene expression of MT and metal transporters were determined in the placenta and in the fetuses. In mother rats, the concentration of Cd in the placenta increased dose-dependently, significantly. The Cd of MT-Cd form and the Cd of non-MT-Cd form increased also dose-dependently. In pathological examination of placenta tissue, syncytial trophoblast cells were damaged dose-dependently, particularly in 5 mg Cd/kg group. In fetuses, the Cd concentration in the total body, liver and kidney increased dose-dependently. The Cd concentration in liver of fetus was significantly higher than that in kidney. In gene expression of metal transporter, gene expression of Zip-8 and ATP7B increased dose-dependently in placenta in 0 mg, 1 mg and 2 mg groups, but the increase was not statistically significant. Based on these results, it was speculated that Cd in placenta is trapped to transport into fetus by MT in placenta. However, non-bound Cd by MT is leaked to fetus by damage of placenta tissue, and it was speculated that non-MT-Cd accumulated in liver of fetus. Namely, it was suggested the possibility that the non-bound Cd by MT is transported by metal transporter of zinc and copper, especially Zip-8 and ATP7B or leaked from the placenta as caused by damage of synsytial trophoblast.

Lead and cadmium levels in cattle muscle and edible tissues collected from a slaughter slab in Nigeria

Contamination levels of lead (Pb) and cadmium (Cd) in muscles, liver and kidney of 50 randomly selected, freshly slaughtered cattle in Ogun State, Nigeria were assessed using an official procedure and atomic absorption spectrophotometry. Results showed that Pb and Cd were present in all of the tested samples. Mean Pb concentrations were 0.721 ± 0.180 mg kg−1, 0.809 ± 0.220 mg kg−1 and 0.908 ± 0.422 mg kg−1 in muscle, liver and kidney tissues, respectively. Mean Cd concentrations were 0.157 ± 0.049 mg kg−1, 0.172 ± 0.071 mg kg−1 and 0.197 ± 0.070 mg kg−1 in muscle, liver and kidney tissues, respectively. Pb and Cd levels in muscle versus kidney tissues and also in liver versus kidney samples were significantly different (p < 0.05). Mean Pb concentrations in all tested tissues were significantly higher than the International Standards while the mean Cd concentrations in liver and kidney samples were within the limits of these standards.

Concentration of heavy and toxic metals Cu, Zn, Cd, Pb and Hg in liver and muscles of Rutilus frisii kutum during spawning season with respect to growth parameters.

Concentration of heavy and toxic metals Cu, Zn, Cd, Pb and Hg were determined in liver and muscles of Rutilus frisii kutum and their relationships with growth parameters (length, age, condition factor) and hepatosomatic index were examined. Thirty-six fish samples were collected from February through March 2009 caught by beach seine in the southwest parts of the Caspian Sea. Atomic absorption and Hg determined concentrations of Cd, Pb, Zn and Cu by vapor method. Cadmium was recorded only in liver samples. Range of other metals in muscle tissue were ND -0.591, 0.001-0.013, 11- 26 and 0.729 -7.261 µg.g -1 dw for Pb, Hg, Zn and Cu respectively. Highest levels of Pb, Zn, and Cu were recorded in muscles Hg and Cd in liver samples. Growth parameters showed a significant relationship with Zn and Cd concentrations in liver samples and only Zn concentrations in muscle samples. There was a positive significant correlation between concentration of Cd in liver and physiological indices (p<0.05). Although higher concentration of Pb was recorded in this study in comparison to previous studies, based on Provisional Tolerable Weekly and daily Intake of fish for human health, kutum is considered safe for human consumption. Considering the results of this study it seems reproductive status of the fish influences heavy metals concentration in liver and muscles of kutum and therefore concentrations of some metals such as Zn and Cu in liver samples may not be a reliable bioindicator for environmental pollution.

Protective effect of theaflavins on cadmium-induced testicular toxicity in male rats

Male Sprague–Dawley rats were treated with cadmium (Cd) (0.4mg/kg body weight, s.c., once a day) and three concentrations of theaflavins (50, 100 or 200mg/kg body weight, orally, once a day) for five weeks to evaluate the protective role of theaflavins on Cd-induced testicular toxicity. After five weeks, serum sex hormone levels, sperm characteristics, DNA damage, oxidant-antioxidant status, Cd content in several organs were measured. The results showed that a low dose of Cd caused testicular toxicity, which was represented by decreased serum testosterone levels, induction of DNA damage, increased malondialdehyde (MDA) content, Cd accumulation in several organs. Administration of theaflavins led to a dose-dependent alleviation Cd-induced damage in testis, including enhanced serum testosterone levels, improved sperm characteristics and abrogation of DNA damage. Theaflavins may also reduce the production of Cd-induced MDA content, decrease Cd concentration in liver, testis and blood, increase Cd content in urine and feces. These findings suggest the use of theaflavins as a potential therapeutic agent for Cd-induced testicular toxicity.

Determination of Cadmium Relative Bioavailability in Contaminated Soils and Its Prediction Using in Vitro Methodologies

In this study, cadmium (Cd) relative bioavailability in contaminated (n = 5) and spiked (n = 2) soils was assessed using an in vivo mouse model following administration of feed containing soil or Cd acetate (reference material) over a 15 day exposure period. Cadmium relative bioavailability varied depending on whether the accumulation of Cd in the kidneys, liver, or kidney plus liver was used for relative bioavailability calculations. When kidney plus liver Cd concentrations were used, Cd relative bioavailability ranged from 10.1 to 92.1%. Cadmium relative bioavailability was higher (14.4-115.2%) when kidney Cd concentrations were used, whereas lower values (7.2-76.5%) were derived when liver Cd concentrations were employed in calculations. Following in vivo studies, four in vitro methodologies (SBRC, IVG, PBET, and DIN), encompassing both gastric and intestinal phases, were assessed for their ability to predict Cd relative bioavailability. Pearson correlations demonstrated a strong linear relationship between Cd relative bioavailability and Cd bioaccessibility (0.62-0.91), however, stronger in vivo-in vitro relationships were observed when Cd relative bioavailability was calculated using kidney plus liver Cd concentrations. Whereas all in vitro assays could predict Cd relative bioavailability with varying degrees of confidence (r(2) = 0.348-0.835), large y intercepts were calculated for a number of in vitro assays which is undesirable for in vivo-in vitro predictive models. However, determination of Cd bioaccessibility using the intestinal phase of the PBET assay resulted in a small y intercept (5.14; slope =1.091) and the best estimate of in vivo Cd relative bioavailability (r(2) = 0.835).

Time-dependent Changes of Cadmium and Metallothionein after Short-term Exposure to Cadmium in Rats

The time-dependent changes in cadmium (Cd) concentration were studied in Female Sprague-Dawley (SD) rats during and after Cd exposure via drinking water (10 and 50 ppm) for 30 days. The cadmium concentration in muscle, liver, kidney, blood plasma, and urine, and the metallothionein concentration in blood plasma were determined every 10 days during exposure and every 7 days after exposure for 3 weeks. The muscle Cd concentration did not change during, and neither after, exposure. The liver Cd concentration increased from 1.4 to 3.3 (at 10 ppm) and from 6.1 to 10.1 folds (at 50 ppm) during exposure and remained higher than those of controls in both groups even during post-exposure period. The kidney Cd concentrations were 2.3 to 5.1 (at 10 ppm) and 4.9-14.0 folds (at 50 ppm) higher than those of controls during exposure and also remained elevated during the post-exposure period. Plasma Cd concentrations were not significantly different from those of controls in both groups. Urine Cd concentrations were more than 2 folds (at 10 ppm) and 6.5 to 12.6 folds (at 50 ppm) higher than those of controls but rapidly decreased over the 7 days of withdrawal. Blood plasma metallothionein concentrations were more than 2.4 folds (at 10 ppm) and 3.1 to 7.4 folds (at 50 ppm) , and they remained elevated till 7 days (10 ppm) and 14 days (at 50 ppm) after exposure. Our data support that Cd in urine could be a useful biomarker during Cd exposure period and metallothionein in blood plasma could be as a supportive biological marker for during and post Cd exposure.

Trace Elements and Metallothionein in Liver and Kidney of Felis catus

Trace metals such as Zn, Cu, and Fe are essential for life; differently, no biochemical function is known for Cd. Changes in dietary metal concentrations can cause deficiency or toxicity. Studies on trace elements in cat are lacking. This paper aimed to analyze Zn, Cu, Fe and Cd concentrations in liver and kidney of pathological domestic cat and to isolate metallothionein (MT) in these tissues. It was not possible to explore a possible correlation between metal concentrations and pathologies because the incidence for each of them was too low. Fe was the most abundant metal; in particular, the liver accumulates average Fe concentrations one order of magnitude higher than Zn and Cu, ranging from 66.75 and 1,444.23 microg/g. Significantly, higher levels of Fe were found in the liver of elder animals. Zn concentrations varied between 26.31 and 84.78 microg/g in the liver whereas in the kidney, ranged between 7.69 and 71.15 microg/g. Cu concentrations were between 2.37 and 112.91 microg/g in liver and between 2.12 and 9.85 microg/g in kidney. Cd was the least abundant metal with the exception of the kidney of the oldest cats where it reached a maximum of 13.71 microg/g. Gel-filtration metal distribution profiles from cytosolic extracts revealed the presence of Cd, Cu, Zn thioneins either in the liver or in the kidney. Because tissue samples were taken from pathological cats from different breed and age, care must be taken to use these data as a baseline profile of trace elements in healthy animals. Our results are indicative that for some specimens the feed levels of Fe and Cu could be higher than the optimal dietary intake and in few cats, there was also an exposure to Cd that was counteracted by MT biosynthesis.

Responses of wild small mammals to a pollution gradient: Host factors influence metal and metallothionein levels

We investigated how host factors (species, age, gender) modulated Cd, Pb, Zn, and Cu concentrations, metallothionein levels (MTs) and their relationships in 7 sympatric small mammal species along a pollution gradient. Cd concentrations in liver and kidneys increased with age in all species. Age effect on other metals and MTs differs among species. Gender did not influence metal and MT levels except in the bank vole. Three patterns linking internal metal concentrations and MTs were observed along the gradient: a low metal accumulation with a (i) high (wood mouse) or (ii) low (bank vole) level of MTs accompanied by a slight or no increase of MTs with Cd accumulation; (iii) an elevated metal accumulation with a sharp increase of MTs (common and pygmy shrews). In risk assessment and biomonitoring perspectives, we conclude that measurements of MTs and metals might be associated because they cannot be interpreted properly when considered separately.

Ascorbic acid, garlic extract and taurine alleviate cadmium-induced oxidative stress in freshwater catfish ( Clarias batrachus)

An experiment was conducted to investigate bioaccumulation potential of cadmium (Cd) and changes in oxidative stress indices in liver and kidney tissues from Cd-exposed catfish ( Clarias batrachus) with or without simultaneous treatment of water with ascorbic acid, garlic extract or taurine. C. batrachus ( n = 324) with average length of 20 ± 4 cm and weight of 86 ± 5 g were used for the present investigation. Fishes were divided into nine groups (I to IX) each comprising 36 fishes. The fishes of groups II, III, IV and V were challenged with 5 ppm of cadmium chloride monohydrate (CdCl 2.H 2O), whereas groups VI, VII, VIII and IX were exposed to 10 ppm CdCl 2.H 2O solution for a period of 45 days. Group I was kept as negative control and the fishes of this group were maintained in water containing no added Cadmium. Group II and VI were maintained as Cd exposed non treated control to serve as positive controls. Fishes of III and VII, IV and VIII, V and IX received ascorbic acid (5 ppm), extract of dried garlic (5 ppm) or taurine (5 ppm), respectively during the entire experiment period. The concentrations of Cd in liver and kidney increased significantly following exposure to Cd and the level continued to rise with the increase in exposure duration. Treatment of tank water with ascorbic acid, garlic or taurine significantly reduced the Cd concentrations in tissues compared to the positive control group, but the level in Cd exposed groups was greater than the negative control group. Fishes exposed to Cd and treated with ascorbic acid, garlic or taurine had reduced oxidative stress as evidenced from lower concentration of lipid peroxides and higher activities of superoxide dismutase and catalase in liver, kidney and erythrocytes compared to fishes exposed to Cd. The reduction in Cd induced oxidative stress was highest in ascorbic acid treated group followed by garlic and taurine treatment. The results suggest that ascorbic acid, garlic and taurine have potential to reduce tissue accumulation of Cd and associated oxidative stress in freshwater catfish.

Cadmium bioaccumulation in three benthic fish species, Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris collected from the Gulf of Gabes in Tunisia

To select a marine teleost fish which can be used as a bioindicator of cadmium (Cd) pollution in the Gulf of Gabes in Tunisia, Cd concentrations in liver and gill were compared in three benthic fish species including Salaria basilisca, Zosterisessor ophiocephalus and Solea vulgaris. Fish samples were collected from three selected sites in the Gulf of Gabes, with different degrees of Cd contamination: the industrialized coast of Sfax (S1), the coast of Douar Chatt (S2) and the coast of Luza (S3). The results shows that Cd concentrations in both sediment and water collected from S1 were significantly higher (p < 0.0001) than those from S2 and S3. For each species, Cd concentrations, in both liver and gill, showed the decreasing order: S1 > S2 > S3. The highest concentration of Cd was detected in the liver of S. basilisca, and only S. basilisca showed bioaccumulation factors (BAF) greater than 1 in all studied sites. In S1 and S2, BAF values respect the following order: S. basilisca > Z. ophiocephalus > S. vulgaris. These results of significant bioaccumulation of Cd, in terms of hepatic concentrations and bioaccumulation factors, indicated that S. basilisca can be used as bioindicator to evaluate the evolution of Cd pollution in the Gulf of Gabes.