Cd Concentrations In Kidney Research Articles

Environmental cadmium and zinc concentrations in liver and kidney of European hare from different Serbian regions

The hares assayed (n=84) were divided into five age groups: 3-6; 12; 12-24; 24-36 and 36 + months. Between all sampling regions (11) significant differences of Cd levels were found in kidney and liver (p value, p=0.001 and 0.007, respectively) . Significant statistical differences (p=0.001) are registered between Cd content in kidney and liver of hares among all represented age groups. Looking at all investigated hare samples, moderately higher concentrations of Zn were found in liver (median value: 25.4 mg/kg w.w) compared to those in kidney (21.4 mg/kg). These differences were statistically significant (p=0.001). Zinc concentrations in liver, between all age groups, did not differ significantly (p=0.512) but in kidney these differences were statistically significant (p=0,001). Significant differences between Zn concentrations in liver in comparison to kidney (pairwise differences) were found within every single age group with exception of the oldest (36+ ) . Strong statistically significant correlations (Ps- Pearson's correlation ) between Cd concentrations in kidney and liver were registered in three groups older than 12 months (Ps=0.81, p=0.001; 0.78, p=0.001; and 0.79, p=0.001, respectively). Negative correlation between Zn and Cd concentrations were found in liver samples within the age group of 12 months (Ps= -0,67, p=0.004). <br><br><font color="red"><b> This article has been retracted. Link to the retraction <u><a href="http://dx.doi.org/10.2298/HEMIND151030061E">10.2298/HEMIND151030061E</a><u></b></font>

Environmental Cd and Zn Concentrations in Liver and Kidney of European Hare from Different Serbian Regions: Age and Tissue Differences

A total of 84 European hares collected from eleven Serbian regions investigated upon cadmium (Cd) and zinc (Zn) presence. Strong statistically significant correlations between Cd concentrations in kidney and liver were registered in animals older than 12 months. Significant differences between Zn concentrations in liver in comparison to kidney were found within every single age group with exception of the oldest. Negative correlation (Ps-Pearson's correlation) between Zn and Cd concentrations were found in liver samples within the age group of 12 months (Ps = -0.67, p = 0.004).

Cadmium accumulation and biochemical parameters in juvenile Persian sturgeon, Acipenser persicus, upon sublethal cadmium exposure

The purpose of the present study was to evaluate the effects of exposure to waterborne sublethal cadmium (Cd) concentration on juvenile Persian sturgeon, Acipenser persicus. Fish were exposed to 0.68 mg/l of Cd for 1, 7, and 14 days, and metal bioaccumulations, biochemical responses, and gill ions were investigated. There were significant differences (p < 0.05) in the kidney (1, 7, and 14) and gills (7 and 14) for Cd concentrations between the control and treatment groups. Also, kidney Cd concentrations were significantly higher (p < 0.05) at metal treatments on day 14 in comparison to day 1. Results showed that there were significant differences (p < 0.05) in plasma glucose and cortisol concentrations between the experimental and control groups on day 1 only, and at metal treatments, a significant decrease (p < 0.05) was observed on days 7 and 14 compared to day 1. No significant alterations were observed in plasma and liver protein contents during the course of the study. Neither triiodothyronine or thyroxine levels nor liver catalase or glutathione-S-transferase activities changed significantly with sublethal dose and with the time. In contrast, liver superoxide dismutase activities were significantly decreased (p < 0.05) at Cd treatments both over the control group and during Cd exposure on days 7 and 14. Finally, a comparison between the groups revealed no differences in gill ion levels for 2 weeks. This study demonstrated that sublethal dose of Cd was stressful for Persian sturgeon and resulted in rapid changes in some of the biochemical parameters.

Health effects of low-level cadmium intake and the role of metallothionein on cadmium transport from mother rats to fetus

Female Wistar rats were given Cd (as CdCl(2)) at a dose of 0, 1, 2, and 5 mgCd/kg/day by gastric tube daily for 6 consecutive days each week for 10 weeks. After the birth, newborn rats were sacrificed on day 1 and at 4 weeks. Mother rats were sacrificed after 4 weeks of lactation The concentrations of Cd in uterus and placenta, and metallothionein (MT) in the uterus of mother rats were determined. The concentrations of Cd in kidney and liver of newborn rats were also determined. Expression of iso-MT genes (I, II, and III) in the uterus of mother rats was measured using RT-PCR. The Cd concentration in the liver of newborn rats at the first day after birth was higher than in the kidney, while the concentration in the kidney of newborn rats at the fourth week after the birth was significantly higher than in the liver. The uterine MT concentration increased with accumulation of Cd; however, the MT concentration did not increase enough to prevent Cd transport to the fetus. On the other hand, it was considered that more Cd was transported as the chemical form of nonMT-Cd from mother rat, and accumulated in the liver rather than kidney of the fetus. Based on analyses of the Cd distribution in the liver and kidney of newborn rats, we speculate that MT in the uterus and placenta does not play a significant role in preventing Cd transport through the placenta from the uterus to the fetus.

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.

Minimal health impact from exposure to diet-sourced cadmium on a population in central Jamaica

Elevated concentrations of naturally occurring Cd have been found mainly in the bauxitic soils of central Jamaica at levels up to 100-1,000 times higher than typical worldwide averages. Some food crops cultivated on these soils absorb significant amounts of Cd. Autopsy studies of kidney Cd concentrations confirm elevated human exposure, and some long-term residents in central Jamaica exceed the general population average by a factor of two. Diet studies have ascertained that a population in central Jamaica is at risk of being exposed to Cd levels in excess of the Provisional Tolerable Weekly Intake (PTWI) set by the WHO of 7 μgCd/kg bodyweight/week, and the EU TWI of 2.5μgCd/kg bodyweight/week. Elevated levels of urine cadmium (U-Cd) and beta-2 microglobulin (β2-MG) concentrations were confirmed with a strong correlation between soil Cd and the U-Cd. Also, higher β2-MG concentrations (>200μg/g creatinine) were found in the population with U-Cd concentrations greater than 2.5μg/L. While this identification is often taken to indicate impairment in the reabsorption capacity of the renal tubules leading to renal disease, there is no evidence in the mortality records of enhanced deaths in central Jamaica compared with the general population resulting from renal disease or diabetes related complications. The highest median age of death in the island is found in Manchester, the parish with the highest average Cd concentration. While we have identified a possible Cd linked renal dysfunction, significant indications of morbidity are not present in the general population.

Alteration in the activity of oxidative enzymes in the tissues of male wistar albino rats exposed to cadmium

The objective of the present study was to investigate the effect of cadmium (Cd) on the activities of some oxidative enzymes [viz Aldehyde oxidase, AO (E.C. 1.2.3.1); Xanthine oxidase, XO (E.C. 1.2.3.2); Sulphite oxidase, SO (E.C.1.8.3.1.); and Monoamine oxidase, MO (E.C. 1.4.3.4)] in the liver and kidney. Male Wistar albino rats were administered 1, 2 and 4 mg Cd(2+)/kg body weight for one and three months. The activities of the oxidative enzymes were subsequently analyzed in the liver and kidney after both periods of exposure. There was a dose dependent increase in liver and kidney Cd concentration in the test rats as compared to control after both periods of treatment with the liver retaining higher concentration of Cd than the kidney for each of the exposure dose. The oxidative enzymes were decreased in a dose dependent manner in the liver and kidney after both periods of treatment. The percentage inhibition of these enzymes was less in the liver of rats treated with Cd for three months relative to the one month treated rats for each of the exposure dose. Conversely, the inhibition of the activities of these enzymes in the kidney of rats in all the treatment groups was more pronounced after three months relative to the trend in the one month treated rats. However, the activities of the oxidative enzymes were higher in the liver as compared to the kidney in all the treatment groups after both durations of Cd treatment. Based on the results obtained, it can be concluded that the inhibition of the oxidative enzymes by Cd may disturb metabolism of bioactive endogenous substances, exogenous components of food and some xenobiotics.

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.

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.

Heavy metal and mineral concentrations and their relationship to histopathological findings in the bowhead whale ( Balaena mysticetus)

The bowhead whale ( Balaena mysticetus) is a species endangered over much of its range that is of great cultural significance and subsistence value to the Inuit of Northern Alaska. This species occupies subarctic and arctic regions presently undergoing significant ecological change and hydrocarbon development. Thus, understanding the health status of the Bering–Chukchi–Beaufort Sea (BCBS) stock of bowhead whales is of importance. In this study, we evaluated the concentrations of six essential and non-essential elements (Zn, tHg, Ag, Se, Cu and Cd) in liver and kidney of bowhead whales ( n = 64). These tissues were collected from the Inuit subsistence hunt in Barrow, Wainwright and Kaktovik, Alaska between 1983 and 2001. Reference ranges of these elements (including previously reported data from 1983–1997) were developed for this species as part of a health assessment effort, and interpreted using improved aging techniques (aspartic acid racemization and baleen isotopic 13C methods) to evaluate trends over time with increased statistical power. Interactions between element concentrations and age, sex and harvest season were assessed. Age was found to be of highest significance. Sex and harvest season did not effect the concentrations of these elements, with the exception of renal Se levels, which were significantly higher in fall seasons. In addition, histological evaluation of tissues from whales collected between 1998–2001 was performed. Associations between concentrations of Cd in kidney and liver and scored histopathological changes were evaluated. Liver Cd concentration was strongly associated with the degree of lung fibromuscular hyperplasia ( P = 0.001) and moderately associated with the degree of renal fibrosis ( P = 0.03). Renal Cd concentration influenced the degree of lung fibromuscular hyperplasia and renal fibrosis ( P = 0.01). A significant age effect was found for both pulmonary fibromuscular hyperplasia and renal fibrosis, indicating age may be a causative factor. Improvements in aging techniques and the addition of histological indices help clarify the relationships between elements and the influence of life history parameters on concentrations of these elements and potential impacts on health. These data provide essential baseline input useful for monitoring the effects of arctic ecosystem change as it relates to global climate change and industrial development, as well as help inform epidemiological studies examining the public health implications of heavy metals in subsistence foods.

How Cadmium Could Compromise the Completion of the European Eel’s Reproductive Migration

The European eel (Anguilla anguilla L.) is severely threatened with extinction. Surprisingly, even though their unusual life cycle makes them particularly vulnerable to pollution, the possible contribution of contamination remains especially poorly known. Here we have investigated the possible effect of cadmium (Cd), a widespread nonessential metal, on eel reproductive capacities. Both control and Cd precontaminated female silver eels were experimentally matured and forced to swim in metal-free conditions to mimic their reproductive migration. Cd pre-exposure was found to strongly stimulate the pituitary-gonad-liver axis of maturing female silver eels leading to early and enhanced vitellogenesis. This was followed by a strong phenomenon of oocyte atresia and eel mortality. These phenomena occurred before oocytes could reach full maturation and were associated with a large entry of both vitellogenin and Cd into the ovaries. Indeed, a redistribution of previously stored cadmium, even from the low Cd levels of control eels, was observed during sexual maturation. Atresia and mortality phenomena were also associated with an overexpression of the pituitary gene encoding the growth hormone, a marker of physiological stress and energy reserves exhaustion. Significantly, these devastating effects of Cd were observed in organisms that presented liver and kidney Cd concentrations still below those observed in eels from Cd contaminated hydrosystems. Our research shows how common levels of cadmium contamination could disrupt endocrine pathways implicated in gonad maturation and subsequently impair reproductive capacity of eel future genitors.

Effect of chlorella supplementation on cadmium metabolism in rats.

This study was conducted to investigate the effect of chlorella on cadmium metabolism in cadmium (Cd) – administrated rats. Sixty Sprague‐Dawley rats (14week‐old) were blocked into 6 groups and fed experimental diets containing different levels of chlorella (0, 3, 5%) and Cd (0 ppm and 160 ppm ) for 10 wks. Cadmium concentrations in blood, liver, kidney, small intestine and feces were measured. Cd concentrations in blood and organ tissues of Cd‐exposed groups were significantly higher than those of Cd‐free groups. However, chlorella intake significantly decreased Cd concentrations in blood and kidney, especially animals fed 5% chlorella diet. Fecal excretion of Cd was highest in 3% chlorella group among Cd‐exposed animals and Cd‐exposed groups excreted significantly higher Cd than Cd‐free groups. The results suggest that chlorella intake decreased Cd concentrations in blood and organ tissues through increasing fecal Cd excretion. *This work was supported by the grants from Daesang.Co.Ltd. and the second stage of Brain Korea 21 project in 2007.

Normal cadmium uptake in microcytic anemia mk/mk mice suggests that DMT1 is not the only cadmium transporter in vivo

Divalent metal transporter 1 (DMT1) is a mammalian iron (Fe) transporter and also transports Cadmium (Cd) in vitro. This study compared Cd absorption in DMT1-dysfunctional MK/Rej- mk / mk mice ( mk/mk mice) and in DMT1-functional, Fe-deficient wild-type (WT) mice, to clarify the role of DMT1 in intestinal Cd absorption in vivo. Mice were given 1 ppm CdCl 2 aq in drinking water for 2 weeks, and the concentrations of Cd and Fe in liver, kidney, and intestinal epithelium were subsequently determined. The Fe concentration in intestinal epithelia of WT mice was decreased in proportion to the level of dietary Fe limitation, while Cd accumulation under the same conditions was increased. DMT1 mRNA expression in the small intestine of Fe-deficient WT mice was clearly increased compared to that in Fe-sufficient WT mice. Iron deficiency resulted in up-regulation of Cd uptake in the intestine of Fe-deficient WT mice. The mk/mk mice have a mutation in DMT1 and loss of its function led to decreased intestinal Fe concentration. However, intestinal Cd accumulation was the same as in WT mice and it was also increased in Fe-deficient situation. There is the possibility that an unknown Cd pathway has taken a role on Cd intestinal absorption in vivo and that this pathway is regulated by food Fe concentrations. Therefore, DMT1 is not the sole transporter of intestinal cadmium absorption in vivo.

Cadmium in the food chain near non-ferrous metal production sites

Dietary cadmium (Cd) exposure was estimated for adults living in Cd-contaminated areas close to non-ferrous metal plants and compared with dietary Cd exposure in the general Belgian adult population. To evaluate the contamination levels of locally produced food items, 35 fruit samples, 97 vegetable samples, 98 samples of potatoes and 53 samples of meat, liver and kidney of cattle, which had resided for more than 18 months in the contaminated area, were analyzed for Cd. Mean Cd concentrations in fruit and vegetables were 1.1- to 9-fold higher than in samples from other regions at ambient Cd levels. Mean Cd concentrations in bovine meat, liver and kidney were 2-fold higher compared to samples from animals in other regions of Belgium. The estimated dietary intake was 31.3 and 63.3 µg day−1 for average and large consumers, respectively, in the contaminated area, compared to 17 and 38.3 µg day−1, respectively, for the general adult population. Excessive consumption of locally produced food items in areas close to non-ferrous metal plants could result in Cd intake levels exceeding the provisional tolerable weekly intake (PTWI).

Induction and metal speciation of metallothionein in wood mice (Apodemus sylvaticus) along a metal pollution gradient

We investigated the binding of Cd, Cu, and Zn to metallothionein (MT) and other metal-binding proteins in free-living wood mice (Apodemus sylvaticus L.) captured in four areas along a metal pollution gradient. We measured total and cytosolic Cd, Cu, and Zn concentrations in mouse liver and kidney by means of inductively coupled plasma-mass spectrometry (ICP-MS). Total (Cu, Cd, Zn)-MT levels were determined in the same tissues by means of the cadmium thiomolybdate saturation assay. Metal speciation of metalloproteins was studied by means of size-exclusion high-performance liquid chromatography-ICP-MS. Liver and kidney of wood mice from the site adjacent to the pollution source showed the highest Cd and Zn concentrations (total and cytosolic) and (Cu, Cd, Zn)-MT levels compared to the other sites farther away from the pollution source. No or only small site differences in tissue Cu concentrations were observed. Almost all the variation (85-95%) in hepatic and renal (Cu, Cd, Zn)-MT levels was explained by the total or cytosolic hepatic Zn and Cd concentration or the renal Cd concentration, respectively. An analysis of the cytosolic metal speciation showed that the Cd-MT, Cu-MT, and Zn-MT fractions in liver and kidney increased significantly with increasing cytosolic metal concentrations. Metals associated with the other cytosolic protein fractions did not increase with increasing exposure. These results illustrate the important role of MT in metal homeostasis and detoxification processes. We conclude that MT is a useful biomarker for environmental metal contamination in free-living wood mice.

Assessment of the Effect of Echinacea purpurea (L.) Moench on Apoptotic and Mitotic Activity of Liver Cells during Intoxication by Cadmium

Cadmium (Cd(2+)) is an important industrial pollutant, although its mechanism of toxicity has not been completely clarified. Cd(2+) is toxic to a wide range of organs and tissues, however, the primary target organs of Cd(2+) toxicity are the liver and kidney. Echinacea purpurea stimulating one or another tread of the immune system stimulates the expression of immunoglobulins and interferons. The experiments were performed on white laboratory mice using intraperitoneal (i.p.) injections 0.05 LD(50) amount of CdCl(2) solution. Two groups of mice were injected by Echinacea purpurea liquid extract: one 0.05 LD(50) and the other 0.1 LD(50). In this article, the Cd(2+) distribution in internal organs, its effect on the mitotic and apoptotic activity of liver cells, as well as effects of Echinacea purpurea liquid extract on Cd(2+)-induced changes in mice were investigated. Cd(2+) concentration in mice blood, liver, and kidney was detected by atomic absorption spectroscopy. Long-term injections of extract of Echinacea purpurea combined with Cd(2+)Cl(2) leads to the significant increase of Cd(2+) concentration in blood and investigated organs of experimental mice. Mitotic and apoptotic activity of liver cells was expressed as the estimated number of mitotic and apoptotic liver cells in randomly selected reference areas in histological slide. Echinacea purpurea decreases the mitotic activity of liver cells induced by Cd(2+) and increases apoptotic activity of the liver cells.

Metal and metallothionein content in tissues from wild and farmed Anguilla anguilla at commercial size

Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel ( Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones. No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in muscle and in all instances these levels were lower than the limits established by the Spanish legislation for fish destined for human consumption.

Cadmium Concentration and Subcellular Distribution in Organs of the Mussel Crenomytilus Grayanus from Upwelling Regions of Okhotsk Sea and Sea of Japan

Cadmium (Cd) accumulation and subcellular distribution in the digestive gland and kidney of mussel Crenomytilus grayanus from naturally Cd elevated areas was studied. Mussels were collected from three sites of Okhotsk Sea and Sea of Japan: control area (site 1), seasonal upwelling region (site 2), and stationary upwelling region (site 3). Mussel from site 3 was shown to accumulate a significantly increased Cd concentration in the digestive gland and an extremely high Cd concentration (1780+/-732 microg g-1 dry weight) in the kidney. Cd was mainly sequestered into the kidney cytosol of the mussels from both upwelling regions and control sites (73% to 96%). However, digestive gland cytosol bound about 55% of Cd for the mussels from sites 1 and 2 and only 22.4% of Cd for the mussel from site 3. In the organs of the mussels from upwelling regions, the most of cytosolic Cd was associated with the protein fraction corresponding to molluscan metallothioneins. MTLP was isolated from kidney cytosol of the mussels from site 3 (powerful upwelling regions) by gel filtration chromatography, whereas in the organs studied of the mussels from other sites, MTLP content was below the detection limit.

Kinetic characterization of Zinc transport process and its inhibition by Cadmium in isolated rat renal basolateral membrane vesicles: In vitro and In vivo studies

We firstly characterized zinc uptake phenomenon across basolateral membrane vesicles (BLMVs) isolated from normal rat kidney. The process was found to be time, temperature, and substrate concentration dependent, and displayed saturability. Zn(2+) uptake was competitively inhibited in the presence of 2 mM Cd with Ki of 3.9 mM. Zinc uptake was also inhibited in the presence of sulfhydryl reacting compound suggesting involvement of [-]SH groups in the transport process. Further, to elucidate the effect of in vivo Cd on zinc transport in BLMVs, Cd nephrotoxicity was induced by subcutaneous administration of CdCl(2) at dose of 0.6 mg/kg/d for 5 days in a week for 12 weeks. An indolent renal failure developed in Cd exposed rats was accompanied with a significantly high urinary excretion of Cd(2+), Zn(2+) and proteins. The histopathology and electron microscopy of kidneys of Cd exposed rats documented changes of proximal tubular degeneration. Notably, Cd content in renal cortex of Cd exposed rats was 215 microg/g tissue that was higher than the critical concentration of Cd in kidneys which was associated with significantly higher Zn and metallothionein (MT) contents. Zinc uptake in BLMVs isolated from kidneys of Cd exposed rats was significantly reduced. Further, kinetic studies revealed that decrease in zinc uptake synchronized with decrease in maximal velocity (V(max)) and increase in affinity constant which is suggestive of decreased number of active zinc transporters. Furthermore, conformational modulation of Zn transporter in BLM was further supported by observed variation in transition temperature for zinc transport in BLMVs isolated from Cd-exposed kidney.