Cd Accumulation In Organs Research Articles

How does silicon alleviate Cd-induced phytotoxicity in barley, Hordeum vulgare L.?

Toxic heavy metal accumulation in edible plants has become a problem worth worrying about for human health. Cadmium is one of the most toxic metals presenting high bioavailability in the environment. The main route of transfer of Cd to humans is the consumption of contaminated food which suggests that reducing of Cd absorption by plants could reduce this risk. In this context, it was suggested that silicon supply would be able to limit the transfer of Cd to the plants. Thus, this work evaluated the effects of 0.5 mM Si on Cd absorption and accumulation in barley (Hordeum vulgare L.). Plants were grown hydroponically for 21 days in the presence of 0 and 15 μM Cd2+ combined or not with 0.5 mM Si. Analyses were related to growth and photosynthesis parameters, Cd accumulation in organs and Cd subcellular distribution in the shoots. Results showed that, under Cd alone, plants showed severe toxicity symptoms as chlorosis and necrosis and produced significantly less biomass as compared to control. 0.5 mM Si in the medium culture significantly reduced Cd-induced toxicity by mitigating symptoms and restoring growth, photosynthesis, and nutrition. Si also induced a significant reduction of Cd concentration in plants and changed its sub-cellular compartmentalization by enhancing fixation to cell walls and reducing the Cd concentration in the cytoplasmic and organelles fractions. These data suggest that the application of Si could significantly increase Cd tolerance and reduce the risk of the Cd accumulation in edible plants.

Cadmium-chelating ability of the siderophore DHBS secreted by Leclercia adecarboxylata FCH-CR2 and its action mechanism

As one of the most accumulative toxic heavy metals, cadmium (Cd) poses a major threat to human health. Bacterial siderophores, as small molecules with metal-absorbing ability, have great potential activity for Cd-reduction. In this study, the siderophore-producing bacterialstrain FCH-CR2 was isolated from a high-Cd contaminated soil using the CAS method. Leclercia adecarboxylata was identified through 16S rRNA sequence, homology analysis, colony morphology, physiological and biochemical tests. A siderophore, catechol type 2,3-dihydroxy-N-benzoyl-l-serine (DHBS) secreted by FCH-CR2, was purified using RP-HPLC and identified by LC-MS/MS. Intraperitoneal injection of DHBS significantly increased fecal Cd levels, and reduced Cd accumulation in organs. In density flooding theory (DFT) analysis, DHBS may bind to Cd via the hydroxyl site on the benzene ring. Besides, the isothermal titration calorimetry (ITC) assay revealed that the formation of Cd-DHBS is a spontaneous and endothermic reaction with ΔG = −21.4 kJ/mol and ΔH = 1.51 ± 0.142 kJ/mol.

Effects of Temperature and Different Feed Uptake on Mercury (Hg) and Cadmium (Cd) Accumulation in Nile Tilapia

Climate warming due to increases in atmospherictemperature and heavy metal contamination constitutesa major issue for the aquatic ecosystem. Heavy metal toxicity hinges on an organism’s tolerable limit ofexposure to these elements, and in the aquatic environment, higher temperatures enhances this toxicity infish. The purpose of this study was to investigate the combined effects of higher temperature and differentfeed uptake on Hg and Cd accumulation in Nile tilapia (Oreochromis niloticus). Fish were exposed to asingle concentration of 10 μg/l mercury (Hg) or 100 μg/l cadmium (Cd) for 30 days under 24 °C (roomtemperature) and 32 °C (elevated temperature) conditions in a 7-L aquaria. The feed used in this experimentcomprised pellets, water and pellets, and water and silkworms, in combination with temperature andheavy metal exposure. Results demonstrated Hg and Cd accumulation in flesh, kidney and liver increasedwith increasing temperature. The influence of different uptake mediahas an effect onHg and Cdconcentration levels in fish organs. The order of Hg and Cd accumulation in organs, from the highest levelto the lowest, was kidney, liver and flesh.

Effects of dietary cadmium on growth, antioxidants and bioaccumulation of sea cucumber (Apostichopus japonicus) and influence of dietary vitamin C supplementation

The effects of dietary cadmium (Cd) supplementation on growth, antioxidant capacity and accumulation of Cd in tissues (body wall, digestive tracts, and respiratory tree) of sea cucumber, Apostichopus japonicus, exposed to sub-chronic concentrations (0, 10, 50, 100, and 500mg Cd/kg dry weight) of Cd were investigated. In addition, the potential protective effects of vitamin C (L-ascorbic acid, AsA) against the effects of Cd on sea cucumbers were investigated. Sea cucumbers were exposed to dietary Cd for 30 days, after which another group of healthy sea cucumbers was supplied diet supplemented with mixed Cd and AsA for another 30 days. Cd exposure for 30 days resulted in increased Cd accumulation in tissues of sea cucumbers with exposure time and concentration. The order of Cd accumulation in organs was digestive tracts>respiratory tree>body wall. On day 30, the body weight gain (BWG) and specific growth rate (SGR) decreased significantly (P<0.05) in the 500mg Cd/kg treatment. Superoxide dismutase (SOD) activity, glutathione peroxidase (GSH-Px) activity and catalase (CAT) activity in the coelomic fluid of sea cucumbers decreased with increasing dietary Cd concentration, but malondialdehyde (MDA) content in the coelomic fluid increased. Providing diet supplemented with Cd and AsA indicated that although sea cucumbers exhibited signs of Cd toxicity, no death occurred in response to 50mg Cd/kg for 30 days. Based on these findings, five treatments were provided: 50mg Cd/kg+0mg AsA/kg, 50mg Cd/kg+ 3000mg AsA/kg, 50mg Cd/kg+ 5000mg AsA/kg, 50mg Cd/kg+10,000mg AsA/kg, and 50mg Cd/kg+15,000mg AsA/kg. The BWG and SGR of sea cucumbers fed the AsA supplemented diet mixed with Cd increased. Additionally, MDA levels in coelomic fluid were negatively correlated with dietary AsA levels, while antioxidant capacities (SOD, GSH-Px and CAT) were positively correlated with dietary AsA levels. Moreover, Cd accumulation in tissues decreased in response to dietary AsA supplementation of treatments. Overall, antioxidant capacity and bioaccumulation in sea cucumber was found to decrease and be induced in response to Cd, but vitamin C mitigated these effects, with 5000mg AsA/kg providing the optimum protection against 50mg/kg Cd.

Lipid peroxidation and HSP72/73 expression in rat following cadmium chloride administration: Interactions of magnesium supplementation

Objective: to determine whether magnesium (Mg) supplementation could have a protective effect against the cadmium (Cd)-induced oxidative stress in liver, kidneys and testes of adult male rats. Stress was evaluated by measuring lipid peroxidation by thiobarbituric acid reactive substances (TBARS) and the heat shock protein (HSP) 72/73 expression. CdCl 2 injections (2.5 mg/day/kg body weight) for 10 days resulted in a time dependent increase of Cd accumulation in liver, kidney and testes, the highest levels being found in liver (400 μg/g dried tissue). At the same time, an increase of lipid peroxidation was observed. The effect was maximal at day 1 of Cd treatment in liver and testes, and later (day 5) in kidney. Then, Cd-induced lipid peroxidation decreased, suggesting the activation of antioxidant defense mechanisms. Injections of Mg SO 4 (300–600 mg/day/kg body weight) reduced in a dose-dependent manner Cd-induced lipid peroxidation in liver and kidney as well as the accumulation of Cd in liver, kidney and testes. In testes, a protective effect of Mg was found only during the early phase of Cd-poisoning. On days 5 and 10, lipid peroxidation was even increased as compared to controls. In liver and testes only the constitutive HSP73 was detected whereas in kidney both HSP73 and the inducible HSP72 were expressed. HSP72/73 expression was not significantly increased by Cd and HSP73 was even lowered in kidney, probably due to the strong dose used. These results were not modified by Mg injections. Conclusion: Mg supplementation can reduce Cd accumulation in organs and lipid peroxidation related to Cd administration.

Cadmium accumulation and elimination in tissues of juvenile olive flounder, Paralichthys olivaceus after sub-chronic cadmium exposure

Experiments were carried out to investigate the accumulation and elimination of cadmium (Cd) in tissues (gill, intestine, kidney, liver and muscle) of juvenile olive flounder, Paralichthys olivaceus, exposed to sub-chronic concentrations (0, 10, 50, 100 μg l −1) of Cd. Cd exposure resulted in an increased Cd accumulation in tissues of flounder with exposure periods and concentration, and Cd accumulation in gill and liver increased linearly with the exposure time. At 20 days of Cd exposure, the order of Cd accumulation in organs was gill > intestine > liver > kidney > muscle and after 30 days of exposure, those were intestine > gill > liver > kidney > muscle. An inverse relationship was observed between the accumulation factor (AF) and the exposure level, but AF showed an increase with exposure time. During the depuration periods, Cd concentration in the gill, intestine and liver decreased immediately following the end of the exposure periods. No significant difference was found Cd in concentration in the kidney and muscle during depuration periods. The order of Cd elimination rate in organs were decreased intestine > liver > gill during depuration periods.

카드뮴 장기노출에 따른 넙치, Paralichthys olivaceus의 기관별 축적

Accumulation of cadmium (Cd) was investigated in organs (gill, liver, kidney, intestine) of olive flounder (Paralichthys olivaceus) exposed to sub-lethal concentration (5, 10, 50, 100 g/L) of Cd for 30 days. Cd exposure resulted in an increased Cd accumulation in liver of flounder for exposure periods and Cd concentration, and Cd accumulation increased linearly with the exposure time. At 20 days of Cd exposure. the order of Cd accumulation in organs was Bill>intestine>liver>kidney and after 30 days of exposure, Cd accumulation in organs was intestine>liver>gill>idney. An inverse relationship was observed between the accumulation factor (AS) and the exposure level, but AE shows an increase with exposure time.

Cadmium accumulation in rat organs after extended oral administration with low concentrations of cadmium oxide.

Rats were exposed to dietary cadmium oxide (CdO) (2.80 and 7.15 ppm Cd) for 60 days. Between days 20 and 36 of the feeding experiment, only 7.15 ppm Cd significantly reduced body weight, while an improved food utilization was recorded at both dietary Cd concentrations between days 36 and 50. After 40 and 60 days of exposure, Cd concentrations of selected organs and tissues and the excreta were recorded by atomic absorption spectroscopy. Compared to the control animals, Cd levels of hair, bone (femur), blood, and testes did not increase. Soft tissues (liver, kidney, lung, and spleen) displayed significantly elevated Cd concentrations after 40 and 60 days in both dosage groups. An increased level of Cd in muscle was observed in one group only (7.15 ppm, day 40). Maximum Cd levels were 11.6 ppm in liver and 9.75 ppm in kidney on a dry weight basis, reflecting a 68- and 50-fold accumulation of the metal compared to the controls. Only absolute weights of lung and liver decreased slightly in the higher dosage group, while relative weights of all organs investigated were not affected by Cd. The ratios in fecal Cd levels between control and CdO-treated animals partly reflected the Cd concentration ratio between the respective diets. No increase in the urinary Cd level was found during the feeding trial. The significance of Cd accumulation in organs, tissues, and excreta and their value as indicators for CdO exposure are discussed.

Modifying effects of host factors in cadmium toxicity: species, sex, and age differences in mice

Experiments were conducted with a view to studying how the factors on the side of the mouse would affect the toxicity of cadmium (Cd) in the acute exposure to it. The factors studied were strain, sex, age in days and the interaction among these. So far these factors have been studied independently. But it is suspected that they are affecting each other, so a simultaneous exploration was attempted in the present study as to the effects of these factors on the Cd accumulation in various organs. The results obtained were as follows: LD50 in acute Cd poisoning tended to be higher in C57BL/6 than in CF#1. Between the sexes it was higher in males than in females. As for the age of the mouse, the LD50 was higher in those aged 40 days and 80 days than in those 20-day- and 150-day-old. Changes in the body weight in acute Cd poisoning were analyzed by obtaining the variance for each factor. As a result a significant difference in the body weight change was revealed between the sexes, strains and ages of the animals and it was indicated that these factors modified the body weight changes in Cd poisoning. Cd concentration in the liver significantly differed among the strains and age groups. In the kidney the Cd concentration had a significant difference among the strains, sexes, ages in days, and interaction between the strain and age, suggesting that these factors might affect the Cd accumulation in the organs. The rate of Cd accumulated against the amount administered (accumulation rate) was studied in each of the organs. In the liver the accumulation rate was significantly affected by the age in days, and the interactions between strain and sex, strain and age, and sex and age, indicating that the modification occurred chiefly through the interactions among the factors. In the kidney the difference in the accumulation rate was attributed to strain, sex, and age in days, indicating that these factors affected the accumulation independently. From these results it was suggested that such factors as strain, sex and age in days affected directly or indirectly the manifestation of toxicity and accumulation of cadmium in the various organs to different degrees.

AN EXPERIMENTAL STUDY ON THE EFFECTS OF SIMULTANEOUS ADMINISTRATION OF CADMIUM AND ZINC ON THE ACCUMULATION OF CADMIUM

An animal experiment with rats was carried out to determine the effects of simultaneous administration of Cd and Zn on the accumulation of Cd in organs during long-term exposure. The diet for Group I contained 50ppm Cd and that for Group II contained 50ppm Cd and 500ppm Zn. Group III was the control group. One-half of the animals in each group were sacrificed after 6 weeks of exposure and the other half after 13 weeks of exposure. Cd, Zn, and Cu concentrations in the liver and the right kidney and Ca concentration in the femur were analyzed. The left kidney was examined histopathologically. The increase of body weight in Group II diminished in the 4th and 5th weeks of exposure, but returned to the normal rate by the 12th week. The average renal Cd concentration of Group I was significantly higher than that of Group II, but no differences was found for that in the liver. Zn accumulation in the liver and the kidney was increased by administration of Cd and it did not depend on the concentration of Zn in diet. No significant intergroup differences were found for Ca concentration in the femur. Cu accumulation in the exposed groups showed a marked increase in the kidney and slight decrease in the liver. Although significant histopathological changes were not observed in the kidney of the exposed groups, some unfavorable influence of Zn on the renal toxicity of Cd was suggested. From these results, it is concluded that Cd accumulation in organs is not influenced by the simultaneous administration of Zn, but Zn concentration increases in the liver and the kidney with Cd exposure.