Comparison of Tissue Metal Concentrations in Zucker Lean, Zucker Obese, and Zucker Diabetic Fatty Rats and the Effects of Chromium Supplementation on Tissue Metal Concentrations

Diabetes results in several metabolic changes, including alterations in the transport, distribution, excretion, and accumulation of metals. While changes have been examined in several rat models of insulin resistance and diabetes, the metal ion concentrations in the tissues of Zucker lean, Zucker obese (an insulin resistance and early stage diabetes model), and Zucker diabetic fatty (ZDF, a type 2 diabetes model) have not previously been examined in detail. The concentration of Cu, Zn, Fe, Mg, and Ca were examined in the liver, kidney, heart and spleen, and Cr concentration in the liver and kidney of these rats were examined. Zucker obese rats have a reduction in the concentration of Cu, Zn, Fe, Mg in the liver compared to ZDF and/or lean Zucker rats, presumably as a result of the increased fat content of the liver of the obese rats. ZDF rats have increased concentrations of kidney Cu compared to the lean rats, while kidney Ca concentrations are increased in the Zucker obese rats. Spleen Fe concentrations are decreased in Zucker obese rats compared to the lean rats. No effects on metal concentrations in the heart were observed between the lean, obese, and ZDF rats, and no effects on Cr concentrations were identified. Cr(III) complexes have previously been shown to have beneficial effects on the signs of insulin resistance in Zucker obese and ZDF rats. The effects of daily gavage administration of chromium picolinate ([Cr(pic)₃]) (1 mg?Cr/kg body mass), CrCl₃ (1 mg?Cr/kg body mass), and Cr3 ([Cr₃O(propionate)₆(H₂O)₃]⁺) (33 μg and 1 mg?Cr/kg body mass) on metal concentrations in these tissues were examined. Treatment with CrCl₃ and Cr3, but not [Cr(pic)₃], at 1 mg?Cr/kg resulted in a statistically significant accumulation of Cr in the kidney of lean and obese but not ZDF rats but resulted in lowering the elevated levels of kidney Cu in ZDF rats, suggesting a beneficial effect on this symptom of type 2 diabetes.     

Acquisition of Cu, Zn, Mn and Fe by mycorrhizal maize (Zea mays L.) grown in soil at different P and micronutrient levels

Sustainability of soil-plant systems requires, among other things, good development and function of mycorrhizal symbioses. The effects of P and micronutrient levels on development of an arbuscular mycorrhizal fungus (AMF) and uptake of Zn, Cu, Mn and Fe by maize (Zea mays L.) were studied. A pot experiment with maize either inoculated or not with Glomus intraradices was conducted in a sand:soil (3 :1) mix (pH 6.5) in a greenhouse. Our goal was to evaluate the contribution of mycorrhizae to uptake of Cu, Zn, Mn and Fe by maize as influenced by soil P and micronutrient levels. Two levels of P (10 and 40 mg kg⁻¹ soil) and three levels of a micronutrient mixture: 0, 1X and 2X (1X contained, in mg kg⁻¹ soil, 4.2 Fe, 1.2 Mn, 0.24 Zn, 0.06 Cu, 0.78 B and 0.036 Mo), were applied to pots. There were more extraradical hyphae at the low P level than at the high P level when no micronutrients were added to the soil. Root inoculation with mycorrhiza and application of micronutrients increased shoot biomass. Total Zn content in shoots was higher in mycorrhizal than non-mycorrhizal plants grown in soils with low P and low or no micronutrient addition. Total Cu content in shoots was increased by mycorrhizal colonization when no micronutrients were added. Mycorrhizal plants had lower Mn contents than non-mycorrhizal plants only at the highest soil micronutrient level. AMF increased total shoot Fe content when no micronutrients were added, but decreased shoot Fe when plants were grown at the high level of micronutrient addition. The effects of G. intraradices on Zn, Cu, Mn, and Fe uptake varied with micronutrient and P levels added to soil. Accepted: 27 December 1999     

Photosynthesis,water-use efficiency and δ<Superscript>13</Superscript>C of five cowpea genotypes grown in mixed culture and at different densities with sorghum

A field experiment involving two planting densities (83,333 and 166,666 plants per ha), two cropping systems (monoculture and mixed culture) and five cowpea [Vigna unguiculata L. (Walp.)] genotypes was conducted at Nietvoorbij (33°54S, 18°14E), Stellenbosch, South Africa, to select cowpea material with superior growth and water-use efficiency (WUE). The results showed significantly higher photosynthetic rates, stomatal conductance and transpiration in leaves of plants at low density and in monoculture due to greater chlorophyll (Chl) levels relative to those at high density and in mixed culture. As a result, C concentration in leaves and the amount of C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B accumulated in shoots at low density and under monoculture were also much higher. Even though no marked differences in photosynthetic rates were found between and among the five cowpea genotypes, leaf C concentration and shoot C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B contents differed considerably, with Sanzie exhibiting the highest C concentration and C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B contents in shoots, followed by Bensogla and Omondaw, while ITH98-46 and TVu1509 had the lowest shoot concentration and contents of C, P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B. WUE (calculated as photosynthate produced per unit water molecule transpired) was significantly greater in plants at low density and monoculture relative to those at high density and in mixed culture. Isotopic analysis revealed significant differences in δ¹³C values of sorghum [Sorghum bicolor L. (Moench.)] and cowpea, with higher δ¹³C values being obtained for plants at low density and in monoculture relative to those at high density or in mixed culture. The five cowpea genotypes also showed significant differences in δ¹³C values, with Sanzie exhibiting the most negative value (i.e. low WUE) and ITH98-46, the least negative δ¹³C value (i.e. high WUE). Whether measured isotopically or from gas-exchange studies, sorghum (a C₄ species) exhibited much higher WUE relative to cowpea (a C₃ species). Both correlation and regression analyses revealed a positive relationship between WUE from gas-exchange studies and δ¹³C values from isotopic analysis of cowpea and sorghum shoots.     

Effects of the Oral Administration of K<Subscript>2</Subscript>Cr<Subscript>2</Subscript>O<Subscript>7</Subscript> and Na<Subscript>2</Subscript>SeO<Subscript>3</Subscript> on Ca,Mg, Mn,Fe, Cu,and Zn Contents in the Heart,Liver, Spleen,and Kidney of Chickens

This study aimed to investigate the effects of selenium on the ion profiles in the heart, liver, spleen, and kidney through the oral administration of hexavalent chromium. Approximately 22.14 mg/kg b.w. K₂Cr₂O₇ was added to water to establish a chronic poisoning model. Different selenium levels (0.00, 0.31, 0.63, 1.25, 2.50, and 5.00 mg Na₂SeO₃/kg b.w.) around the safe dose were administered to the experimental group model. Ca, Mg, Mn, Fe, Cu, and Zn were detected in the organs through flame atomic absorption spectrometry after these organs were exposed to K₂Cr₂O₇ and Na₂SeO₃ for 14, 28, and 42 days. Results showed that these elements exhibited various changes. Ca contents declined in the heart, liver, and spleen. Ca contents also decreased on the 28th day and increased on the 42nd day in the kidney. Mn contents declined in the heart and spleen but increased in the kidney. Mn contents also decreased on the 28th day and increased on the 42nd day in the liver. Cu contents declined in the heart and spleen. Cu contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Zn contents declined in the heart and spleen. Zn contents increased on the 28th day and decreased on the 42nd day in the liver and kidney. Fe contents decreased in the heart and liver. Fe contents increased on the 28th day and decreased on the 42nd day in the spleen and kidney. Mg contents did not significantly change in these organs. Appropriate selenium contents enhanced Mn and Zn contents, which were declined by chromium. Conversely, appropriate selenium contents reduced Ca, Fe, and Cu contents, which were increased by chromium. In conclusion, the exposure of chickens to K₂Cr₂O₇ induced changes in different trace elements, and Na₂SeO₃ supplementation could alleviate this condition.     

Copper Uptake and Its Effect on Metal Distribution in Root Growth Zones of Commelina communis Revealed by SRXRF

To explore the copper uptake mechanisms by the Cu-tolerant plant Commelina communis, the contents of Cu and other metals (including Fe, Zn, and Mn) in roots were detected using atomic absorption spectrometer under transporter inhibitors, partial element deficiency, or Cu excess treatments, while distribution characters of Cu and other metals in root growth zones were investigated by synchrotron radiation X-ray fluorescence spectroscopy (SRXRF). Cu uptake was inhibited by the uncoupler DNP and P-type ATPase inhibitor Na₃VO₄, not by the Ca²⁺ ion channel inhibitor LaCl₃, suggesting that Cu could probably be assimilated actively by root and be related with P-type ATPase, but not through Ca²⁺ ion channel. Fe or Zn deficiency could enhance Cu uptake, while 100 μM Cu inhibited Fe, Zn, and Mn accumulation in roots significantly. Metal distribution under 100 μM Cu treatment was investigated by SRXRF. High level of Cu was found in the root meristem, and higher Cu concentrations were observed in the vascular cylinder than those in the endodermis, further demonstrating the initiative Cu transport in the root of C. communis. Under excess Cu stress, most Fe was located in the epidermis, and Fe concentrations in the endodermis were higher than those in the vascular cylinder, suggesting Cu and Fe competition not only in the epidermal cells but also for the intercellular and intracellular transport in roots. Zn was present in the meristem and the vascular cylinder similar to Cu. Cu and Zn showed a similar pattern. Mn behaves as Zn does, but not like Fe.     

Effect of dietary chitosans on trace iron, copper and zinc in mice

Dietary chitosans with different molecular weight M_w and the degree of deacetylation DDA (high molecular weight chitosan HCS with M_w 7.60 × 10⁵ and DDA 85.5%, middle molecular weight chitosan MCS with M_w 3.27 × 10⁴ and DDA 85.2%, chito-oligomer COS with M_w 0.99 × 10³ and DDA 85.7% and water-soluble chitosan WSC with M_w 3.91 × 10⁴ and DDA 52.6%) were used at the 1.05% level to feed mice for 90 days. Afterwards no pathological symptoms, clinical signs or deaths were observed. The body weight of mice in chitosan group and control group showed no significant difference. Although HCS, COS and WSC had no significant effect on the level of Fe, Zn and Cu in the tested mice’s liver, spleen, heart and kidney, MCS significantly increased the level of Fe, Zn and Cu in liver. Therefore dietary ingestion of chitosan did not depress the level of Fe, Zn and Cu in mice.     

Iron plaque formation on wetland plants and its influence on phosphorus,calcium and metal uptake

We investigated Fe plaque formation and Ca, Cu, Mn, Zn, and P uptake capacities of fifteen kinds of wetland plants. The test plants were cultured in 3 l nutrient solutions for 8 days. Fe plaque was induced by adding 200 mg l⁻¹ Fe²⁺ as FeSO₄·7H₂O for 4 days in one set of experiment and 8 days in another. This plaque ranged from 2.38 to 8.67 mg g⁻¹ of plant root after 4 days and from 4.56 to 15.71 mg g⁻¹ of plant root after 8-day treatment. In both experimental durations, the plaque was significantly correlated with root surface area (r = 0.904 and 0.878, P < 0.01). Thus, Canna generalis, Typha latifolia and Thalia dealbata, with their larger root surface areas (>1,400 cm²), formed relatively greater Fe plaque amounts. The amounts of Ca, Cu, Zn and P in the Fe plaques were significantly correlated with Fe plaque amount, (r = 0.819, 0.742, 0.693, 0.917, respectively, for these four elements for the 4-day treatment; and r = 0.917, 0.768, 0.949, 0.872, respectively, for 8-day treatment, P < 0.01). Plants varied widely in accumulating Ca, Cu, Mn, Zn, and P in their tissues. The amounts accumulated on root were significantly correlated with Fe plaque amount in both for 4- and 8-day exposure treatments with Fe (r = 0.973, 0.847, 0.709, 0.837, 0.892, respectively, for 4-day treatment; and r = 0.943, 0.691, 0.843, 0.957, 0.983, respectively, for 8-day treatment, P < 0.01). No such significant correlations were found for the Fe plaque in shoot. Canna generalis, Typha latifolia and Thalia dealbata were superior in Ca, P and Zn uptake, while Canna generalis and Thalia dealbata accumulated Cu and Mn well in case of concentrated wastewater treatment.     

Comparison between levels of trace elements in normal and cancer inoculated mice by XRF and PIXE

Determination of Rb, Br, Se, Zn, Cu, Fe, and Br/Rb ratio in tissues of mice inoculated with colon and melanoma cancer cells is described. A group of 19 Balb/c mice inoculated with C26 colon carcinoma, 4 C57B1/6 mice inoculated with B16 melanoma, and 13 control mice of both kinds were under investigation. The study was conducted on samples of blood, liver, kidneys, colon, and skin, and the trace element levels in normal and inoculated mice were compared. The inoculation was by subcutaneous injection either at the back or intrafootpad. The blood samples were taken 1, 2, and 3 wk after inoculation, and after 4 wk all the animals were sacrificed. Two nondestructive, complementary analytical methods were used: a modified X-ray fluorescence (XRF) for solid tissue and particleinduced X-ray emission (PIXE) for blood samples. The detection limit (DL) in the PIXE method was 0.35 (μg/g dry wt in 600 s counting time and in XRF, 1 μg/g dry sample for Rb, Br, Se and Zn and 2 μg/g for Cu and Fe in 200 s counting time. In all the cases studied, cancerous tissue developed at the site of the injection, and a significant difference in the trace element levels was observed between tissue samples obtained from normal and inoculated mice. The most pronounced effect was an increase in Rb level in the tumor by a factor ranging between 4 and 10 relative to normal tissue, with a corresponding decrease in the Br/Rb ratio (p < 0.05). Smaller changes were found in the Br, Se, Zn, and K levels. The changes in trace element levels in the inner organs were much smaller and seem to be influenced by the site of injection.     

Sequential changes in Fe,Cu, and Zn in target organs during early Coxsackievirus B3 infection in mice

In Coxsackievirus B3 (CB3) infection, the heart and pancreas are major target organs and, as a general host response, an associated immune activation and acute phase reaction develops. Although iron (Fe), copper (Cu), and zinc (Zn) are involved in these responses, sequential trace element changes in different target organs of infection have not been studied to date. In the present study, Fe, Cu, and Zn were measured through inductively coupled plasma mass spectrometry (ICP-MS) in the plasma, liver, spleen, heart, and pancreas during the early phase (d 1 and 3) of CB3 infection in female Balb/c mice. The severity of the infection was assessed through clinical signs of disease and histopathology of the heart and pancreas, including staining of CD4 and CD8 cells in the pancreas. During infection, the concentrations of Fe, Cu, and Zn changed in the plasma, liver, and pancreas, but not in the spleen and heart. The changes in plasma Cu, Zn, and Fe seemed to be biphasic with a decrease at d 1 that turned into increased levels by d 3. Cu showed similar biphasic changes in the liver, spleen, and pancreas, whereas, for Zn and Fe, this pattern was only evident in the liver. In the pancreas, the reverse response occurred with pronounced decreases in Fe (23%, p < 0.05) and Zn (64%, p < 0.01) at d 3. Although the pathophysiological interpretation of these findings requires further research, the sequential determination of these elements may be of clinical value in enterovirus infections in deciding the stage of disease development.     

Characterization of natural variation for zinc, iron and manganese accumulation and zinc exposure response in Brassica rapa L.

Brassica rapa L. is an important vegetable crop in eastern Asia. The objective of this study was to investigate the genetic variation in leaf Zn, Fe and Mn accumulation, Zn toxicity tolerance and Zn efficiency in B. rapa. In total 188 accessions were screened for their Zn-related characteristics in hydroponic culture. In experiment 1, mineral assays on 111 accessions grown under sufficient Zn supply (2 μM ZnSO₄) revealed a variation range of 23.2–155.9 μg g⁻¹ dry weight (d. wt.) for Zn, 60.3–350.1 μg g⁻¹ d. wt. for Fe and 20.9–53.3 μg g⁻¹ d. wt. for the Mn concentration in shoot. The investigation of tolerance to excessive Zn (800 μM ZnSO₄) on 158 accessions, by using visual toxicity symptom parameters (TSPs), identified different levels of tolerance in B. rapa. In experiment 2, a selected sub-set of accessions from experiment 1 was characterized in more detail for their mineral accumulation and tolerance to excessive Zn supply (100 μM and 300 μM ZnSO₄). In this experiment Zn tolerance (ZT) determined by relative root or shoot dry biomass varied about 2-fold. The same six accessions were also examined for Zn efficiency, determined as relative growth under 0 μM ZnSO₄ compared to 2 μM ZnSO₄. Zn efficiency varied 1.8-fold based on shoot dry biomass and 2.6-fold variation based on root dry biomass. Zn accumulation was strongly correlated with Mn and Fe accumulation both under sufficient and deficient Zn supply. In conclusion, there is substantial variation for Zn accumulation, Zn toxicity tolerance and Zn efficiency in Brassica rapa L., which would allow selective breeding for these traits.     

Increased urinary excretion of zinc and copper by mercuric chloride injection in rats

The effects of HgCl₂ on urinary excretion of Zn, Cu and metallothionein at different time intervals were observed in male Wistar rats. The rats were given a daily intraperitoneal injection of²⁰³HgCl₂ (0.5 or 1.0 mg Hg kg^–1) for 2 days.²⁰³Hg, Zn, Cu and metallothionein in urine, kidney and liver were analyzed. Significant increases in urinary Zn and Cu concentrations were found in HgCl₂-dosed groups. Elevated urinary Zn and Cu concentrations were accompanied by an increased metallothionein excretion in urine at different time periods. Zn concentration in urine remained elevated during the entire observation period of 7 days. There were also increased concentrations of Cu and Zn in the renal cortex in one of the two exposed groups. The results indicate that urinary Cu and Zn are related to the manifestation of renal toxicity and/or the synthesis of metallothionein in kidney induced by mercury.     

Effects of Ellagic Acid on Copper,Zinc, and Biochemical Values in Serum and Liver of Experimental Cholestatic Rats

Ellagic acid (EA) is a natural polyphenolic compound. Although, modulator effects of EA on copper (Cu) and zinc (Zn) levels in some liver diseases have been reported in experimental animals, its effects in obstructive jaundice (OJ) has not been clarified. We aimed to evaluate potential effects of EA on Cu and Zn levels in liver and serum of cholestatic rats. Forty Wistar albino rats were equally divided into four groups. First group was used as controls. Second group received EA (60 mg⁻¹ kg⁻¹ day⁻¹) for 8 days. Third was OJ group, and fourth group was OJ plus EA group. After 8 days, blood and liver samples were obtained. Higher serum and liver Cu and lower serum and liver Zn levels were found in OJ group (p < 0.05) compared with other groups. However, these differences reached to significant levels for Cu in serum and for Zn in lever. Higher serum copper levels were decreased, and lower liver Zn levels were increased by EA treatment in cholestatic rats (p < 0.05). Also, higher Cu/Zn ratio in OJ group was decreased by EA treatment both in liver (p < 0.05) and in serum (p < 0.05). Significantly higher serum bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase values were found in OJ and OJ + EA groups compared with the control and EA groups (p < 0.05). In conclusion, result of the current study indicated that ellagic acid has modulator effects on Cu and Zn levels in liver and serum of cholestatic rats.     

Phytotoxic effects of Cu, Zn, Cd and Pb on in vitro regeneration and concomitant protein changes in Holarrhena antidysenterica

The nodal explants of in vitro shoots of Holarrhena antidysenterica L. were cultured on Murashige and Skoog's (MS) medium augmented with 15 μM N⁶-benzyladenine (BA) alone (control) or supplemented with different concentrations (1, 5, 10 and 20 mg dm⁻³) of CdCl₂, CuSO₄, Pb(NO₃)₂ and ZnSO₄. The maximum morphogenic response in terms of average shoot number (4.95 ± 0.17) was seen in control. ZnSO₄ proved to be less inhibitory in comparison to CuSO₄, Pb(NO₃)₂ and CdCl₂. None of the explants cultured on CdCl₂ containing medium induced multiple shoots. Maximum protein content [3.80 ± 0.04 mg g⁻¹(f.m.)] was observed in control and slightly less [3.50 ± 0.02 mg g⁻¹(f.m.)] in tissues exposed to 1 mg dm⁻³ of CuSO₄ and minimum [1.00 ± 0.02 mg g⁻¹(f.m.)] in Zn treated (20 mg dm⁻³) explants. SDS-PAGE analysis of the treated tissues revealed that two new polypeptides (29 and 20 kDa) in response to Cu and Zn treatment, respectively, have been synthesized.     

Effects of interaction between65Zn,cadmium, and copper in rats

Distribution and retention of zinc in the presence of cadmium and copper was studied in rats exposed repeatedly to these metals. The experiment was performed on white rats of the Wistar strain. The animals were divided into four groups/five rats each: 1)⁶⁵ZnCl₂; 2)⁶⁵ZnCl₂+CdCl₂; 3)⁶⁵ZnCl₂+CuCl₂; and 4) control group. Rats were administered sc every other day for two weeks:⁶⁵ZnCl₂−5 mg Zn/kg; CdCl₂−0,3 Cd/kg; and CuCl₂−2 mg Cu/kg. The zinc content was measured in rat tissues by γ-counting. Effect of Cd and Cu on subcellular distribution of zinc in the kidney and liver and on the level of metallothionein were also examined. Whole body retention of zinc under the influence of cadmium was lower than that observed in animals treated with zinc alone. However, copper increased twofold the whole body retention of zinc. Cadmium elevated the accumulation of zinc only in the kidneys nuclear fraction and liver soluble fraction. In the kidneys and liver, copper elevated the accumulation of zinc, in the nuclear, mitochondrial, and soluble fractions. The level of metallothionein-like proteins (MT) in the kidneys after a combined supply of zinc and copper was significantly increased with respect to the group of animals treated with zinc alone. These results indicated complex interactions between cadmium, copper, and zinc that can affect the metabolism of each of the metals.     

Effects of oral aluminum on essential trace elements metabolism during pregnancy

The present study was conducted to assess in rats the effects of oral aluminum (Al) exposure on calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) accumulation and urinary excretion. Three groups of plug-positive Sprague-Dawley (SD) rats were given by gavage 0, 200, and 400 mg/kg/d of Al(OH)₃ on gestational days 1–20. Three groups of nonpregnant female SD rats of the same age received Al(OH)₃ by gavage at the same doses for 20 consecutive days. At the end of the treatment period, 24-h urine samples were collected for analysis of Al and essential elements. Subsequently, all animals were sacrificed and samples of liver, bone, spleen, kidneys, and brain were removed for metal analyses. With some exceptions, the urinary amounts of Al, Mn, and Cu excreted by pregnant animals as well as the urinary levels of Al excreted by nonpregnant rats were higher in the Al-treated groups than in the respective control groups. Although higher Al levels were found in the liver of pregnant rats, the concentrations of Al in the brain of these animals were lower than those found in the same tissues of nonpregnant rats. With regard to the essential elements, tissue accumulation was most affected in pregnant than in nonpregnant animals. In pregnant rats, the hepatic and renal concentrations of Ca, Mg, Mn, Cu, Zn, and Fe, as well as the levels of Ca in bone, and the concentrations of Cu in brain were significantly higher in the Al-exposed groups than in the control group. According to the current results, oral Al exposure during pregnancy can produce significant changes in the tissue distribution of a number of essential elements.     

Effects of different proteins on the metabolism of Zn, Cu, Fe, and Mn in rats

Many factors are known to influence trace element metabolism and one of them is dietary protein. The present study examines the effects of casein, soybean protein, and peanut protein on the metabolism of the Zn, Cu, Fe, and Mn in growing rats. The results showed that Zn, Fe, and Mn excretions in the feces of peanut protein-fed rats (PPERs) were similar to that of casein-fed rats (CPFRs) (p>0.05), whereas all of the Zn, Cu, Fe, and Mn excretions in the urine of PPFRs were significantly higher than that of CPFRs (p<0.05), but its apparent absorption rate (AAR) of Cu, Fe and its apparent retention rate (ARR) of Cu were all higher than that of CPFRs (p<0.05). Hepatic Zn content of soybean protein-fed rats (SPFRs) was higher than that of CPFRs and PPFRs (p<0.05 respectively) and serum, renal, and femoral Cu contents of SPFRs were significantly lower; however, hepatic Cu, and renal Mn contents were significantly higher than that of CPFRs (p<0.05, respectively); The hepatic Fe content of SPFRs was significantly higher than that of CPFRs and PPFRs (p<0.01, respectively). To sum up, compared to casein, soybean protein might be a good dietary source to make up for Zn and Fe deficiency, and also peanut protein to make up for Cu and Fe deficiency.     

Effects of iron,copper, zinc,calcium, and magnesium on human lymphocytes in culture

The effects of simultaneous changes of calcium, magnesium, iron, copper, and zinc concentrations were evaluated in normal human T and B lymphocytes, cultured in cation-depleted media. Optimal concentrations for thymidine incorporation (TI) in both cell populations were Fe and Zn 15 μM and Cu 5 μM; for t cells Ca 2 mM and Mg 4 mM; for B cells Ca 4 mM and Mg 6 mM. TI decreased with increasing molarity of cations and the decrease was particularly apparent with Cu. Minimal amounts of Ca and Mg (0.5 mM) were necessary for growth, even in presence of optimal concentrations of Fe, Cu, and Zn. Fe and Cu showed synergistic stimulatory effects at low concentrations and synergistic inhibitory effects at high concentrations. Antagonism between Fe and Zn, Cu and Zn, and Ca and Zn was also demonstrated. CD4/CD8 increased with PHA stimulation in presence of Zn, and decreased with ConA stimulation in presence of Zn or Fe. The results demonstrate: (1) the relationship and interdependence of Fe, Cu, and Zn concentrations in modulating the growth of normal lymphocytes; (2) the stimulatory effects of Fe on B cells and Zn on CD8 positive cells; (3) the inhibitory effect of Cu at concentrations lower than those of Fe and Zn; (4) the requirement of Ca and Mg in certain concentration and ratio for the action of the other cations; and (5) the Ca and Mg requirement for the growth of B cells higher than T cells.     

Microbial degradation of ethylenediaminetetraacetate in soils and sediments

[¹⁴C]ethylenediaminetetraacetate (EDTA) was shown to be slowly biodegraded to ¹⁴CO₂ in soils and sediments under aerobic conditions and by microorganisms in mixed liquid culture. EDTA chelates of Cu, Cd, Zn, Mn, Ca, and Fe added to soil were equally degraded, while Ni-EDTA was degraded more slowly.     

lipid peroxidation in liver of mice administrated with nickel chloride

The relationship between Ni-induced hepatic lipid peroxidation (LPO) and the concentrations of Ni and trace elements was investigated in male ICR mice. The protective effects of antioxidants were also examined. Hepatic LPO and the concentrations of Ni, Fe, Cu, and Zn in the liver were enhanced after an ip injection of nickel chloride (NiCl₂). Dose-response studies were conducted on male mice with different groups being injected with 50, 85, and 170 μmol Ni/kg. LPO increased significantly in a dose-dependent manner. In time-course studies, mice were administrated NiCl₂ (170 μmol Ni/kg) and killed at intervals of 6, 12, 24, and 48 h after injection. Both LPO and the accumulation of Ni, Fe, Cu, and Zn in the liver showed a significantly positive time-course relationship after NiCl₂ injection. At 1 h and 24 h after a single ip injection of 170 μmol Ni/kg, the mice were given an ip injection of ascorbic acid (vit C), glutathione (GSH), and selenium (Se). Vit C and GSH significantly decreased both the level of hepatic LPO and the concentration of Ni in the liver, but did not decrease the accumulation of Fe, Cu, and Zn. However, LPO in the experimental group of mice was different significantly from that in the control group. In conclusion, the results suggest that Ni-induced hepatic LPO may result from increasing the amounts of Ni, Fe, and Cu, since these elements are involved in the generation of hydroxyl radical by inducing the Fenton reaction, thus instigating the Ni-mediated hepatic LPO. The protective effects of vit C and GSH in hepatic LPO result not only from removing the oxygen reactive species, but also from decreasing the Ni concentration.     

Iron,copper, and zinc status in rats fed supplemental nickel

Literature data concerning the effect of increasing dietary Ni concentrations on Fe, Cu, and Zn status in rats are sparse and, in part, controversial. Therefore, the effects of the addition of either 0, 3, 50, or 100 mg Ni/kg diet on Fe, Cu, and Zn status of rats were investigated in two separate experiments. Purified diets were used that were composed according to the established nutrient requirements of rats. Ni in kidney was increased with increasing Ni intakes. Dietary Ni did not significantly influence Fe concentrations in plasma, liver, kidney, femur, and spleen. Likewise, the addition of Ni to the diet did not alter Cu status. Zn concentrations in femur were significantly decreased after feeding the diets with 100 mg Ni/kg. However, Zn in plasma, liver, kidney, and spleen was not affected. It is concluded that variations in dietary Ni concentrations have no major impact on Fe, Cu, and Zn status in rats.