Cadmium In Liver Research Articles

The use of enriched 111Cd as tracer to study de novo cadmium accumulation and quantitative speciation in Anguilla anguilla tissues

In order to determine de novo incorporation of cadmium into fish liver and kidney, the stable isotope 111Cd was used as tracer and the European eel (Anguilla anguilla) as model organism. The exposure of animals to 111Cd (100 ng L−1) gave rise to the in vivo dilution of the natural previously existing Cd in the selected tissues and therefore a change of Cd isotope ratios can be measured. The measurement of this new 114Cd/111Cd ratio by ICP-MS, and the subsequent application of mathematical calculations based on the isotope dilution methodology, allowed us to quantitatively discriminate between the previously accumulated natural Cd and the isotopically enriched Cd (de novo incorporated). This was observed for total cadmium in liver and kidney and also for speciated Cd (e.g., that bound to different cytosolic fractions, such as the Metallothionein fraction (MT fraction). In addition, the quantitative results observed pointed out that in liver natural Cd decreased, while kidney received an appreciable amount of endogenous cadmium, supporting the idea that a redistribution of Cd between liver and kidney in fish occurs, as has previously been described in mammals. Moreover, Cd speciation analysis provided the real cadmium balance (natural Cd versus enriched Cd) in the MT fraction, demonstrating quantitatively the Cd mobilization in hepatic and renal MT fractions. On the other hand, since MTs bind Cd, they were capable of in vivo incorporation of the enriched and stable isotope 111Cd during the period of exposure. The separation of the 111Cd labelled MTs was accomplished by anion-exchange (AE) chromatography, which was coupled on-line with ICP-MS detection to investigate the in vivo ability of individual liver MT isoforms for binding cadmium. The 114Cd/111Cd ratio, measured in three individual MT isoforms, was comparatively lower in the predominant MT-2a isoform, which seems to act in the preferential incorporation of the new incoming Cd. On the other hand, the determination of Cd in separated MT isoforms (by an on-line post-column isotope dilution technique) in conjunction with the calculated Cd isotope ratios has allowed for the first time the determination of both recently (exogenous) and previously (endogenous) Cd bound to individual MT isoforms. The results shown here could open the way to the study of other metalloproteins metals preferences, where radioactive techniques are inadequate for metal speciation analysis.

Safety and storage stability of horse meat for human consumption

Most horse meat is consumed by humans and/or animals in the region where it is produced. However, horse meat for human consumption is exported in large quantities from the Americas and in lesser quantities from Eastern Europe, to Western Europe and Japan where it is often eaten raw. Horse meat prepared to a good hygienic condition should not be prone to early microbial spoilage, but contamination of the meat with Salmonella and Yersinia enterocolitica may be relatively common, and infection of the meat with Trichinella may occur occasionally. Those organisms from horse meat could cause disease when the raw meat is eaten. Moreover, accumulation of cadmium in horse liver and kidney may render those tissues unsafe for human consumption.

Public health evaluation of cadmium concentrations in liver and kidney of moose ( Alces alces) from four areas of Alaska

Liver and/or kidney samples were collected from 139 hunter-killed moose from four areas of Alaska during 1986. The concentration of cadmium in organ tissue was determined by direct-current plasma atomic emission spectrometry. All results are reported as μg/g wet weight. Concentrations of cadmium in liver ranged from 0.06 μg/g to 9.0 μg/g; in the kidney cortex they ranged from 0.10 μg/g to 65.7 μg/g. Cadmium levels were significantly associated with location and age. The highest geometric mean liver (2.11 μg/g) and kidney cortex (20.2 μg/g) cadmium concentrations were detected in moose harvested near Galena, Alaska. Limited dietary information from Alaska and Canada indicates that the intake of moose liver or kidney does not exceed, in most individuals, the World Health Organization recommendations for weekly cadmium consumption of 400 μg to 500 μg. Additionally, human biomonitoring data from Canada and Alaska indicate exposure to cadmium is low except for individuals who smoke cigarettes. Given the nutritional and cultural value of subsistence foods, the Alaska Division of Public Health continues to support the consumption of moose liver and kidney as part of a well-balanced diet. Human biomonitoring studies are needed in Alaska to determine actual cadmium exposure in populations with a lifelong history of moose liver and kidney consumption.

Concentrations of heavy metals in the tissues of red deer (Cervus elaphus) from the region of Warmia and Mazury, Poland

Cadmium, lead, copper and zinc were quantified using a validated ICP/MS method in the tissues and organs of 82 specimens of red deer of different sexes and ages, which had been hunted at the Great Lakes Land region in the north-eastern of Poland in 2000–01. Copper and zinc occurred in liver, kidney and muscle tissue of red deer at concentrations of 6.4–29, 3.3–7.2 and 1.9–6.4, and of 19–43, 17–41 and 19–64 mg kg−1, respectively, which are considered typical for the species, age and gender compared with values noted for some other wild and domestic ruminant species elsewhere. For cadmium and lead, the concentrations decreased in the order kidney > liver > muscle tissue, with overall means of 2.2, 0.19, and 0.10, 0.31, and 0.26, 0.22 mg kg−1 wet weight, respectively. The cadmium content of the kidney of a proportion of red deer sampled exceeded the legal tolerance limits set in Poland. The means (but not individual animal data) obtained for cadmium in kidney and liver correlated (0.99) with the age of red deer. Also, the lead content of the muscle meat of red deer for many carcasses exceeded the legal limit, which was probably due to contamination from the fine dust particle remains from the lead bullets used.

Distribution of Cadmium and Lead in Liver and Kidney of Some Wild Animals in Slovakia

The content of cadmium and lead, as risk factors of environment, in liver and kidneys of wild animals as brown hare (Lepus europaeus), yellow-necked mouse (Apodemus flavicollis), wood mouse (Cleithrionomys glareolus), and red deer (Cervus elaphus) were studied. Samples were analyzed by the atomic absorption spectrophotometry method (AAS). The highest levels of cadmium were found in kidneys (0.213–2.387 mg/kg) of all animal species. The concentration of cadmium in liver was 0.032–0.258 mg/kg. The analysis of lead showed that the concentration of this element was higher in kidneys of yellow-necked mouse and wood mouse (0.503–0.780 mg/kg) than in liver (0.177–0.268 mg/kg). In brown hare and red deer a higher accumulation of lead in liver (0.221–1.904 mg/kg) in comparison with kidneys (0.115–0.561 mg/kg) is reported.

Hydroxyl radical production and oxidative damage induced by cadmium and naphthalene in liver of Carassius auratus

Freshwater goldfish ( Carassius auratus) were exposed to cadmium (Cd) from 0 to 5 mg/L, and naphthalene (NAP) from 0 to 50 mg/L. Twenty-four hours after the exposure, reactive oxygen species (ROS) was trapped by phenyl- tert-butyl nitrone and detected by electron paramagnetic resonance (EPR). Protein carbonyl (PCO) and lipid peroxidation (LPO) content were determined. The activities of superoxide dismutase (SOD) and catalase (CAT) were also measured. The EPR spectra signals were characterized by prominent six-line spectra, which were defined as hydroxyl radical ( OH). As compared to the control group, Cd and NAP significantly induced OH production marked by the intensity of the prominent spectra at higher concentrations. Both xenobiotics also increased LPO content and PCO content, depending on the concentrations. Either LPO or PCO content showed significant relation with OH production. Cd increased the activity of SOD and decreased that of CAT at 5 mg/L, and NAP increased the activities of SOD and CAT at 5 mg/L. The results clearly indicated that these two structurally different non-redox cycling xenobiotics could induce OH generation and result in oxidative damage in liver of C. auratus, and these effects were concentration-dependent.

Concentration of Selected Metals in Liver, Kidney, and Muscle of the Red Deer (Cervus elaphus)

Concentration of cadmium, lead, chromium, zinc, copper, and manganese in liver, kidney, and muscle of red deer was investigated. For analysis of the content of these trace elements an AAS method was used. The concentration of cadmium was significantly (p < 0.05) higher in kidney in comparison with liver and muscle. The level of lead was the highest in muscle (p < 0.05). Lower values were detected in liver and in kidney. The concentration of chromium was very similar in all studied tissues. A higher concentration of zinc was found in muscle, followed by kidney and liver. The level of copper was significanlty higher in liver (p < 0.05), and lower in kidneys and muscle. In evaluation of the concentration of manganese in red deer, the highest concentration of this element in liver was detected.

Heavy Metal Contamination of European Eel (Anguilla anguilla) and Brown Trout (Salmo trutta) Caught in Wild Ecosystems in Spain

In this study we analyzed the pattern of copper (Cu), cadmium (Cd), lead (Pb), and mercury (Hg) accumulation in liver (as a detoxifying organ) and muscle (as the most important tissue for human consumption) of brown trout (Salmo trutta) and European eel (Anguilla anguilla) caught in two wild Spanish rivers where both species are usually angled for human consumption. Cd, Pb, and Cu accumulated preferentially in the liver of both species. Hg accumulated both in the liver and muscle in brown trout, whereas it accumulated preferentially in muscle in European eel. Both high metal content and preferential accumulation of Hg in muscle suggest that European eel is more harmful than brown trout for human consumption.

Detoxification mechanism of heavy metals in marine mammals and seabirds: interaction of selenium with mercury, silver, copper, zinc, and cadmium in liver.

Subcellular distribution of mercury, selenium, silver, copper, zinc, and cadmium was determined in the liver of northern fur seals (Callorhinus ursinus), black-footed albatrosses (Diomedea nigripes), and Dall's porpoises (Phocoenoides dalli). Mercury, selenium, and silver were preferentially accumulated in nuclear, lysosomal, and mitochondrial fraction with an increase in their hepatic concentrations, whereas copper, zinc, and cadmium were accumulated mainly in cytosol with an increase in the hepatic concentrations for all three species. To gain insight into the existing state of the metals, they were extracted with four extractants--sodium dodecylsulfate (SDS); 2-mercaptoethanol; 2-mercaptoethanol + guanidinium thiocyanate; and copper sulfate (CuSO4)--at several concentrations from nuclear, lysosomal, and mitochondrial fraction in liver from a specimen of northern fur seal. Extraction efficiencies of the metals for 2-mercaptoethanol + guanidinium thiocyanate and CuSO4 were much higher than those for SDS and 2-mercaptoethanol. Also, for all individuals of the three species, metals were extracted by the three extractants--2% SDS; 0.25 mol/L 2-mercaptoethanol + 5 mol/L guanidinium thiocyanate; and 0.1 mol/L CuSO4--from nuclear, lysosomal, and mitochondrial fraction of liver. In the northern fur seals with higher concentration of mercury, the molar ratio of selenium to mercury approached unity in the nonextractable fraction of 0.25 mol/L 2-mercaptoethanol + 5 mol/L guanidinium thiocyanate, suggesting the possible formation of mercuric selenide (HgSe) with increasing hepatic concentration. Because the nonextractable content of mercury and its distribution were larger for black-footed albatross than those for the other two species, it was suggested that the black-footed albatross has a stronger ability to form a stable compound(s) of mercury in the liver. It is notable that the existing state of silver was similar to that of mercury as judged by their subcellular distribution and the extraction tests, suggesting that silver also interacted with selenium in the liver of marine animals used in this study.

Metal concentrations in selected organs and tissues of five Red-knobbed Coot (&lt;i&gt;Fulica cristata&lt;/i&gt;) populations

The Red-knobbed Coot Fulica cristata is an abundant aquatic bird in South Africa and was anticipated to have indicator abilities for metal pollution. This hypothesis was tested on 83 coot samples collected from five selected aquatic ecosystem areas supporting substantial coot populations, of which various abiotic and biotic components are known to contain varying levels of a number of metals. The aim of this study was achieved by determining the variations in Cd, Cu, Ni and Pb concentrations in liver, kidney, bone and blood samples, with the use of standard flame atomic absorption spectrophotometry techniques. Coots from the Germiston Lake sampling site showed the highest concentrations of cadmium in liver (2.2 µg/g d.w.) and kidney (5.4 µg/g d.w.). The absence of metalprocessing industries in the catchments of the Florida Lake and the Steynsrus farm dams reflects the low liver and kidney concentrations of Cd, Ni and Cu, respectively. The blood of the Natalspruit wetland coots contained the highest dry weight concentrations of Ni (11.4 µg/g), Cd (1.8 µg/g) and Cu (14.4 µg/g). The statistical evaluation points towards small-scale geographical differences, especially in the concentrations of Cu, Ni and Pb and in the liver, kidney and blood. However, in terms of actual metal concentrations recorded, no significant differences existed between coots of the reference site (Steynsrus farm dams) and those from the other four localities. It is concluded that the impact of metal-containing diets on the tissue concentrations of these metals in birds plays a far more significant role compared to the migratory habits or short-range movements of the coots.

Postnatal development of hepatic oxidative, hydrolytic and conjugative drug-metabolizing enzymes in female horses

Little is known about the effects of aging on the hepatic drug metabolizing capacity of horses despite the relatively long lifespan characterizing this species. A wide array of cytochrome P450 (CYP)-dependent monooxygenases, carboxylesterases and transferases were assayed in liver microsomes from 50 female horses in an age range between less than 1 year to over 12 years. Rather unexpectedly, both the CYP content and the activity of NADPH cytochrome c reductase rose as a function of age. Accordingly, a general increasing trend was recorded in the rate of the in vitro metabolism of the substrates reported to be related to CYP2B-, CYP2E- or CYP3A, although, as detected by Western immunoblotting, only the levels of proteins recognized by anti-rat CYP3A- and CYP2B antibodies appeared to increase consistently. Also the carboxylesterases and uridindiphosphoglucuronyl-transferase (UGT) activity toward 1-naphthol displayed a similar trend, glutathione S-transferase accepting 3,4-dichloronitrobenzene as a substrate being the only enzyme activity showing an age-related decline. A positive correlation was also found between liver cadmium content and CYP amount as well as the activities of most monooxygenases (except for those related to CYP1A), carboxylesterases, and UGT. While confirming that a number of enzyme activities are less expressed in foals, our results contradict the general view that the drug metabolizing capacity drops in elder individuals. Although several other factors can influence the kinetics of foreign compounds in aged animals, data from this study may provide insight in understanding possible age-related differences in drug efficacy and the response to toxic substances in horses.

Using the Mallard to biomonitor heavy metal contamination of wetlands in north-western Poland

Contents of iron, zinc, copper, manganese, nickel, lead and cadmium were determined in the brain, pectoral muscle, kidney, liver and bones of the Mallard (Anas platyrhynchos), a cosmopolitan, herbivorous duck species. Both immature (im; in the first year of life) and older (adult, ad) ducks were studied. The birds originated from wetlands in two areas in north-western Poland, one located in the Słońsk waterfowl reserve (n=32 im+24 ad) and the other near the city of Szczecin (n=21 im+21 ad). There were numerous significant age-dependent differences in the metal contents of the organs of the Mallards obtained from near Szczecin (Sz) and/or Słońsk (S). Copper contents in the brain (Sz and S), muscles (Sz) and kidneys (Sz) as well as cadmium contents in the liver (Sz, S), kidneys (Sz, S) and muscles (S) were observed to increase with age. Between-area differences in metal contents of individual organs were recorded as well. The S Mallard showed higher contents of iron and copper (in muscles, liver and kidneys), zinc (in liver and kidneys) and cadmium (in muscles, liver and kidneys), while the Sz ducks revealed higher contents of manganese and lead (in brain and bones). The differences observed may be related to the habitat specificity: the Słońsk reserve is periodically flooded by the River Odra (Oder) waters that carry pollutants from a copper mining area 250 km away. On the other hand, the mid-field ponds near Szczecin are affected by pollutants, including those that are manganese-rich, generated by agriculture and traffic.

Using the Mallard to biomonitor heavy metal contamination of wetlands in north-western Poland

Contents of iron, zinc, copper, manganese, nickel, lead and cadmium were determined in the brain, pectoral muscle, kidney, liver and bones of the Mallard ( Anas platyrhynchos), a cosmopolitan, herbivorous duck species. Both immature (im; in the first year of life) and older (adult, ad) ducks were studied. The birds originated from wetlands in two areas in north-western Poland, one located in the Słońsk waterfowl reserve ( n=32 im+24 ad) and the other near the city of Szczecin ( n=21 im+21 ad). There were numerous significant age-dependent differences in the metal contents of the organs of the Mallards obtained from near Szczecin (Sz) and/or Słońsk (S). Copper contents in the brain (Sz and S), muscles (Sz) and kidneys (Sz) as well as cadmium contents in the liver (Sz, S), kidneys (Sz, S) and muscles (S) were observed to increase with age. Between-area differences in metal contents of individual organs were recorded as well. The S Mallard showed higher contents of iron and copper (in muscles, liver and kidneys), zinc (in liver and kidneys) and cadmium (in muscles, liver and kidneys), while the Sz ducks revealed higher contents of manganese and lead (in brain and bones). The differences observed may be related to the habitat specificity: the Słońsk reserve is periodically flooded by the River Odra (Oder) waters that carry pollutants from a copper mining area 250 km away. On the other hand, the mid-field ponds near Szczecin are affected by pollutants, including those that are manganese-rich, generated by agriculture and traffic.

Toxic and essential trace metals in muscle, liver and kidney of bovines from a polluted area of Morocco

Toxic and essential trace metals were measured in muscle, bone, liver and kidney of bovine grazing on the municipal wastewater spreading field of Marrakech City (Morocco). Bovines were found to be seriously contaminated by toxic metals, especially cadmium, and levels were higher in liver and kidney, specific target organs for metal bioaccumulation. The high cadmium content seemed to contribute to a reduction in zinc and copper levels. The arithmetic mean concentrations of zinc, copper and cadmium in liver and kidney, were respectively: 126, 112 and 5.1 μg/g in liver; 89, 33 and 10.3 μg/g in kidney.

Accumulation of Lead, Cadmium, and Mercury in Liver and Kidney of the Brown Hare (Lepus europaeus) in Relation to the Season, Age, and Sex in the West Slovakian Lowland

Concentrations of lead, cadmium, and mercury in liver and kidneys of brown hares in relation to season, age, and sex were investigated. Over a period of one year 74 hares, 36 males and 38 females were analyzed. The concentrations of lead and cadmium were analyzed by AAS and mercury was determined by mercury vapor technique. The median concentration of lead in liver as well as in kidney in relation to the season is the highest in winter period in comparison with spring, summer, and summer period (p<0.001). The highest concentration of cadmium was found in winter, but the differences were not significant. In mercury, we report significantly higher (p<0.001) median concentrations in liver (0.023 mg kg−1) as well as in kidney (0.068 mg kg−1) in winter period in comparison with all other observed periods. In relation to age the concentrations in lead and mercury in liver and kidney were very similar, without significant differences. In cadmium we report significantly higher concentrations in the liver as well as kidney in adult animals (0.154 and 1.521 mg kg−1) in comparison with juvenile animals (0.048 and 0.582 mg kg−1, respectively). In comparison of the female and male brown hares we found significantly higher (p<0.05) median concentration of lead in the liver of males (0.216 mg kg−1) than in females (0.127 mg kg−1) and the level of cadmium is significantly higher (p<0.001) in females (1.464 mg kg−1) than in male brown hares (1.384 mg kg−1).

Liver Histopathology of the Southern Watersnake, Nerodia fasciata fasciata, Following Chronic Exposure to Trace Element-Contaminated Prey from a Coal Ash Disposal Site

Previous studies have demonstrated the accumulation of arsenic, cadmium, selenium, strontium, and vanadium in livers of Southern Watersnakes fed fish from a coal-ash contaminated site. Our study is the first to investigate effects of trace element accumulation on cytology of snake liver. Snakes were born in the laboratory and raised for one or two years on diets consisting of varying proportions of contaminated fish. The majority (71%) of snakes fed contaminated prey did not exhibit any differences in liver histology when compared to control snakes fed an uncontaminated diet. In the remaining contaminant-exposed snakes, some aberrations were noted. The most prevalent pathology involved the proliferation of collagen fibers that resulted in narrowing or occlusion of sinusoids and increasing the mass of the intersinsuoidal parenychma. Fibrosis of the liver as a result of chronic injury has been reported previously in reptiles, but this is the first report that links such tissue damage to dietary contamination.

Simultaneous determination of copper, lead, cadmium, zinc, and selenium in cow liver by differential pulse polarography

A fast and simple method was established for the determination of trace elements in liver. DP polarograms of wet digested liver samples were taken in acetate buffer, pH about 4, for lead, cadmium, and zinc determinations. For copper, addition of EDTA at pH 4 was needed for a better separation from the iron peak. Selenite ion was determined using the hydrogen catalytic peak after the addition of Mo(VI) to the same solution. Trace element levels were different for two separate sections of liver. For the first section (S1) the quantities were found to be 8.12 ± 0.21 mg g–1 Cu, 1.16 ± 0.12 mg g–1 Zn, 1.09 ± 0.11 mg g–1 Cd, 0.59 ± 0.07 mg g–1 Pb, and 2.05 ± 0.22 mg g–1 Se, in dry liver. For the second section (S2) the results were the same for selenium, but Cd was too small to be detected. The other trace element quantities were 0.48 mg g–1 Cu, 0.22 mg g–1 Pb, and 0.29 mg g–1 zinc. The validity of the method was demonstrated with a synthetic sample resembling liver composition. This method enabled the simultaneous determination of heavy trace elements such as copper, lead, cadmium, molybdenum, selenium, and zinc by using an inexpensive instrument and without any separation or pre-concentration procedures.Key words: cow liver, determination, differential pulse polarography, trace elements.

Identification of cadmium-sensitive genes in the Antarctic fish Chionodraco hamatus by messenger RNA differential display

To investigate the ability of cadmium to affect gene transcription in fish, the messenger RNA (mRNA) differential display technique was used to analyze gene expression in the Antarctic icefish Chionodraco hamatus exposed to sublethal doses of cadmium salt. Seven DNA complementary to RNA (cDNA) bands whose steady-state levels of expression significantly changed in response to cadmium exposure were identified. The results obtained show that two groups of genes are affected by cadmium in icefish liver. The first group comprises genes that are up-regulated by the metal: in particular, a gene encoding the heat-shock protein HSP70 and another encoding a protein homologous to GP49 of Sparus aurata egg envelope. The other group comprises genes down-regulated by cadmium. These are the transferrin gene and a gene encoding a protein presenting homology to mouse T2K, a kinase having a role in the prevention of apoptosis. Three cDNAs had no homology to known gene sequences, thus suggesting that may either encode not yet identified proteins, or correspond to untranslated regions of mRNA molecules.

Kidney, liver and bone cadmium content in the western sandpiper in relation to migration.

Cadmium content was measured in kidney, liver and tarsus bones of western sandpipers (Calidris mauri) at a temperate migratory stopover site (Fraser Delta, British Columbia, Canada) and a wintering site (Playa el Agallito, Chitre, Panama) over a two year period. Cadmium content in liver and kidney was age and sex dependent. Adult females generally had lower kidney and liver cadmium than adult males (P < 0.05), but a sex difference was not detected in juveniles. Cadmium increased with age in kidney, liver and to a lesser extent in bone (P < 0.001) with average "steady-state" kidney and liver content being reached within the sandpipers first year. In general, tissue cadmium residues in adult males and females were independent of sampling location although for bone, site-specific differences did occur (P < 0.001). Bone cadmium was lower in females sampled from their wintering grounds as compared to temperate stopover sites suggesting that bone cadmium may be mobilized during periods of feather molt. Comparison of cadmium residues among sandpipers of increasing age suggest that exposure is occurring along the Pacific Coast, at stopover sites as the birds migrate north to Alaska and south to Panama. This study points to the importance of considering the ecology of the species (e.g., in this case migratory behavior) in interpreting trace metal residues.

Cadmium and lead levels in human liver and kidney samples obtained from Bursa Province

Autopsy samples of liver and kidney from 43 Turk cadavers obtained from the Department of Forensic Medicine of Bursa City were analysed for cadmium and lead. All subjects were born between 1918 and 1982. The means of cadmium residue levels were found to be 0.63235 - 0.06345 ppm in the liver and 0.8507 - 0.077 ppm in the kidney. The means of lead residue levels were measured as 0.44675 - 0.0591 ppm in the liver and 0.42905 - 0.0528 ppm in the kidney. In addition, the cadavers were grouped according to sex, age and place of dwelling, city or village. Although samples contained both of the metals in their normal levels, it was concluded that these results do not indicate whether both of the metals will be a serious threat to public health in the future.