Metal composition of human hepatic and renal metallothionein

This article is based on data on the levels of metals (Cd, Zn, Cu) and metallothionein (MT) determined radiochemically with²⁰³Hg in renal cortex and liver of 137 autopsy cases. From this number, for 23 cases, the gel filtration of the cytoplasmic fraction of the organs was performed. The molar content of metals in the MT fraction (Sephadex G-50) amounted to 46.9, 50.2, and 2.0% for Cd, Zn, and Cu in renal cortex, respectively, and to 8.3, 83.6, and 9.1% for Cd, Zn, and Cu in the liver, respectively. In parallel with the increase of Cd and MT in renal cortex, increasing saturation was found of the MT fraction by Cd, occurring at the expense of Zn and Cu. Equimolar amounts of Cd and Zn in the MT fraction are found at Cd level of 0.5 μmol Cd/g wet wt of renal cortex. In the liver, analogous dependency (elevation of %Zn, depression of %Cd and %Cu) were observed in relation to Zn and MT levels in this organ. The basic level of Zn (not bound with MT) was estimated at 0.5 μmol/g for both renal cortex and liver. A deficit of non-MT Zn in kidneys is proposed as an alternative mechanism of toxic Cd action.     

Age-dependent changes in metallothionein levels in liver and kidney of the Japanese

Samples of liver, renal cortex, and medulla were obtained from 55 forensic autopsies (0- to 95-yr-old Japanese). Metallothionein (MT) was determined by the Ag-hem or Cd-hem method. Zinc (Zn), copper (Cu), and cadmium (Cd) were determined by atomic absorption spectrophotometry. The mean levels of MT were 250 μg/g in the liver, and 394 μg/g (cortex) and 191 μg/g (medulla) in the kidney. Age-dependent changes were observed in both the liver and kidney. In the liver, MT level decreased during infancy and increased thereafter with age. Similar age-dependent changes in the levels of Zn and Cu were observed. In the kidney cortex, MT level increased with age, although no correlation was found after middle age. The levels of Cd and Zn also increased with age until middle age; however, they decreased thereafter. These results suggest that age-dependent changes in renal MT levels are associated with accumulation of Cd.     

Effects of pretreatment with cadmium on the discriminative uptake of subsequent cadmium, copper or zinc by the liver

1. Effects of pretreatment with cadmium (Cd) on the uptake by the liver of subsequent Cd, copper (Cu) and zinc (Zn) were examined at two different time intervals to elucidate the biological discrimination mechanism among metals of similar chemical properties. 2. Pretreatment with 0.3 mg Cd/kg body wt 6 hr but not 24 hr before a subsequent dose of 0.8 mg metal/kg body wt enhanced the disappearance rate from plasma and accumulation rate in the liver of Cu (and Zn) but not of Cd. 3. Synthesis of metallothionein was induced with different time-courses depending on the time interval between the pretreatment and subsequent treatment, which coincided with the accumulation curves for Cu (and Zn) but not for Cd. 4. Although uptake of Cd was not enhanced by any pretreatment, metallothionein synthesis was enhanced depending on the timing of pretreatment.     

Heavy Metal Accumulation and Ecological Responses of Turfgrass to Rubbish Compost with EDTA Addition

Domestic rubbish compost is a complex-polluted system, containing multiple heavy metals,which limits its application. In the present study, Cr, Mn, Ni, Cu, Zn, Cd, and Pb accumulation and ecological responses of turfgrass to rubbish compost were investigated following the addition of EDTA. The results showed that the addition of EDTA significantly increased heavy metal accumulation in Lolium perenne L.and Festuca arundinacea L. Most heavy metal concentrations in L. perenne increased with increasing EDTA supply. The concentrations of Cr, Mn, Ni, Cu, and Cd in L. perenne were highest following the addition of 30 mmol/kg EDTA and the concentrations of Cr and Ni at this point reached concentrations of1914.17 and 521.25 μg/g, respectively. When the EDTA level was ＜ 20 mmol/kg, the accumulation of most heavy metals in F. arundinacea increased with increasing EDTA supply, but showed a tendency to decrease at EDTA concentrations ＞20 mmol/kg. The highest concentrations of Mn, Ni, Cu, and Zn in F.arundinacea reached 268.01, 110.94, 161.52 and 1 354.97 μg/g, respectively, following the addition of 20mmol/kg EDTA. The EDTA-induced increase in the accumulation of heavy metals in turfgrass was plantand metal-specific. L. perenne had a relatively high ability to accumulate Cr, Ni, and Zn. The highest Zn concentration was 2 979.58 μg/g and, following the addition of EDTA, the concentrations of the three metals were increased 26.23, 20.03, and 10.49-fold, respectively, compared with control. However, F. arundinacea showed a high ability to accumulate Cr, with the highest concentration (596.02 μg/g) seen following the addition of 30 mmol/kg EDTA; the concentration of Cr increased 15.51-fold compared with control. With EDTA addition, ecological responses of both turfgrass species showed that EDTA at concentrations ＜10mmol/kg increased seed germination and aboveground net primary production (ANP) of L. perenne and slightly inhibited those of F.arundinacea, but EDTA at concentrations ＞20 mmol/kg inhibited these parameters significantly for both species. Moreover, EDTA increased the chlorophyll and proline content at all concentrations tested. On the basis of the synthetic remediation index, the optimal EDTA concentration for turfgrass remediation of heavy metals in compost is approximately 10 mmol/kg.     

Metal concentrations in the liver and kidney of aquatic mammals and penguins

We determined the hepatic and renal concentrations of Cd, Pb, Zn, Cu, and Fe in (1) marine mammals (three bottle-nosed dolphins, six California sea lions, and one sea otter), (2) freshwater and brackish-water mammals (one Oriental short-clawed otter and four European river otters), and (3) sea birds (three rock-hopper penguins, two king penguins, three Humboldt penguins, four Macaroni penguins, and four Magellanic penguins), all of which were kept in a zoo and an aquarium in Japan. We investigated the species-specificity of Cd accumulation in these aquatic animals. We also presented the basic data on metal concentrations. The concentrations of Cd in liver and kidney tended to be higher in marine mammals than in freshwater mammals. Many penguins, sea birds, showed high Cd concentrations. These results suggest that the habits of these animal species may be involved in accumulation of Cd. Pb concentrations were below the detection limit or low in both liver and kidney [not detected (ND)=0.132 μg/g and ND=0.183 μg/g, respectively]. The hepatic concentrations of Zn and Cu were high in young animals. In penguins, a positive correlation was found between the Zn and Cd concentrations in the liver and kidney and between the Cu and Cd concentrations in the liver. Individual variation was large in Fe concentration (48–3746 μg/g in the liver and 51–980 μg/g in the kidney).     

Concentrations of cadmium,zinc, copper,iron, and metallothionein in liver and kidney of nonhuman primates

To evaluate the species specificity of Cd accumulation and the relationship of Cd with other essential metals and metallothionein (MT), the concentrations of Cd, Zn, Cu, and Fe in the liver and kidney and the MT concentrations in the soluble fractions of the liver and kidney were determined in Cd-uncontaminated nonhuman primates (11 species, 26 individuals) kept in a zoo and two wild-caught Japanese macaques. The compositions of metal-binding proteins in the soluble fractions were also investigated by high-performance liquid chromatography (HPLC). The hepatic Cd concentration was 0.03–14.0 μg/g and the renal Cd concentration was 0.35–99.0 μg/g, both varying greatly and being higher in nonhuman primates, which were more closely related to man. The hepatic Zn concentration was 24.0–176 μg/g and the renal Zn concentration was 13.5–138 μg/g, showing 7- to 10-fold differences, and a correlation (r=0.558, p<0.01) was found between renal Zn and renal Cd concentrations. It was proved that in the liver, MT is more closely correlated with Zn (r=0.795, p<0.001) than with Cd (r=0.492, p<0.01) and that in the kidney MT is correlated with both Cd (r=0.784, p<0.001) and Zn (r=0.742, p<0.001). HPLC analysis of metals bound to MT-like protein in chimpanzees, de Brazza’s monkeys, and Bolivian squirrel monkeys showed that more than 90% of Cd in both the liver and kidney, approx 40% of Zn in liver and 28–69% of Zn in kidney were bound to MT-like protein. The higher percentage Zn was bound to high-molecular protein.     

On metallothionein,cadmium, copper and zinc relationships in the liver and kidney of adult rats

1. A short-term exposure of adult Wistar rats to Cu (50 μg/ml) and Cd (10.0 μg/ml drinking water) caused significant changes in the subcellular concentrations of Cd, Cu, Zn and metallothionein (MT) in the liver and kidney; the concentrations were close to the physiological values, however.2. To establish a relationship between these changes in the subcellular concentrations of Cd, Cu, Zn and the level of MT in the post-mitochondrial fraction of the liver and kidney, the analytical data (N = 42) were subjected to the multiple regression analysis.3. The analysis showed that MT synthesis in the liver was principally induced by small amounts of Cd (0.32–1.4 μg/g wet wt) whereas in the kidney a level of MT in the post-mitochondrial fraction correlated positively with the renal Cd and Cu, as well as with the level of this protein in the liver.4. The above results together with the positive correlation between the level of MT in the post-mitochondrial fraction and the concentration of Cu in this fraction, as well as the fact that under normal physiological conditions the capacity of MT (β-domain) in the liver and kidney was sufficient to bind 50–100% of the total post-mitochondrial Cu suggest that MT, first induced by small amounts of Cd, may be involved in the metabolism of Cu.     

Influence of cadmium on the distribution of the essential trace elements zinc and copper in the liver and kidneys of rats

Cd induced changes of Zn and Cd distribution in the liver and kidneys were studied in relation to Cd metallothionein (MT) synthesis. Wistar male rats were given CdCl₂ by sc injection of .8, 1.5, and 3.0 mg Cd/kg three times a week for three weeks. Cd levels of liver and kidneys increased with the increment of Cd dosage and 80–90% of Cd was found in the cytosol. The MT fractions contained 80–89% cytosolic Cd in the liver and 55–75% Cd in the kidneys. Zn concentrations in the liver increased following Cd administration, But Zn in the kidneys showed only slight increase. There was a distinct decrease of Cu concentration in the liver of the 3.0 mg group. In contrast, Cu concentrations in the kidneys increased about three times in the .8 and 1.5 mg Cd groups, but Cu in the 3.0 mg group showed only 1.5 times increase. The changes of these metal concentrations were observed mainly in the cytosol. Non-MT-Cd in the kidneys was maximum in the 1.5 mg group, but the 3.0 mg group showed significant decrease. In parallel with this decrease of Cd, Cu and Zn in the kidneys showed similar decrease. When the kidneys are injured, Zn and Cu appear to leak from this organ.     

牛组织重金属含量与饲养环境的相关性

通过选择不同污染程度的区域进行取样,分析了贵州地区不同污染水平下牛组织中重金属(Cu、Zn、Pb、Cd)的含量和与饲养环境的相关性.结果表明:贵州不同污染水平下牛组织中的Cu、Zn基本符合国家食品卫生要求,Pb只有污染地区的肝脏和肾脏超过限量标准,Cd污染较严重,除非污染区肝脏外,牛肾脏和肝脏中Cd的平均含量均超过国家肉类制品卫生限量标准,但肌肉组织符合卫生标准;牛组织重金属元素含量与饲养环境中的土壤、饲料和饮用水源的重金属含量和污染程度密切相关,尤其是肾脏组织,其相关系数r＞0.78.饲料向牛组织的重金属迁移系数,随饲料元素含量的增加而逐渐降低,其中Cd的迁移系数最大,Pb的迁移系数最低;必需元素和有害元素在不同组织中的比值,随污染程度的增加而降低.肾脏的Cu/Cd和Zn/Cd值比其它组织低得多,Cd主要在肾脏中蓄积,Cu主要在肝脏组织蓄积,Zn主要在肌肉和肝脏,Pb主要在肾脏和肝脏.     

Metal accumulation and metallothionein in brown trout, Salmo trutta, from two Norwegian rivers differently contaminated with Cd, Cu and Zn

In this work we have studied the accumulation of heavy metals in two brown trout (Salmo trutta) populations in their natural environment and the participation of metal binding to metallothionein (MT) in this process. Cd, Cu and Zn concentrations, total MT (including Cu MT) and Cd/Zn MT were measured in the gills, liver and kidney of trout inhabiting two rivers, one Cu-contaminated and the other Cd/Zn-contaminated, located at Røros, Central Norway. In both populations, high levels of Cu were found in the liver, whereas Cd was accumulated in liver and particularly in the kidney. The proportions of Cd/Zn MT and Cu MT in liver and kidney, but not in gills, reflected the accumulated and the environmental concentrations of these metals. The total Cu MT concentrations in the investigated tissues, however, were highest in trout from the river with the lowest ambient Cu concentration. It is suggested that MTs are of less importance in Cu-acclimated trout. The data also suggest that acclimation to a Cu-rich environment involves reduced Cu accumulation or increased Cu elimination. In trout from the Cd-rich environment, this metal was mainly bound to MT, whereas in trout from the Cu-rich environment Cd was also associated with non-MT proteins. These findings emphasize the importance to determine both Cd/Zn MT and Cu MT levels, when the participation of this protein in metal handling in trout tissues is investigated.     

Evidence for a synergistic interaction between cadmium and endotoxin toxicity and for nitric oxide and cadmium displacement of metals in the kidney.

This study was undertaken to examine changes in Zn and Cu homeostasis in the liver and kidney of rats caused by cadmium (Cd) or lipopolysaccharide (LPS) administration. Twenty-five male, 7- to 8-week-old Wistar rats were divided into five groups: saline only treatment, saline treatment and food deprivation, exposure to a single dose of Cd, exposure to LPS alone, and exposure to Cd + LPS. Changes in plasma nitrate concentrations and hepatic and renal Zn and Cu contents were measured together with urinary excretion rates for the metals and nitrate on 3 consecutive days: 24 h before treatment and 24 and 48 h after treatments. Cd exposure alone for 48 h caused a nearly 2-fold increase in plasma nitrate levels with no changes in urinary nitrate excretion whereas LPS treatment caused plasma nitrate levels to increase by 10-fold and urinary nitrate excretion to increase by 4-fold. Administration of LPS 24 h after Cd exposure caused a 10-fold increase in plasma nitrate concentrations and a 100-fold increase in urinary nitrate excretion compared to the rates prior to LPS administration. These results indicate a synergistic interaction between Cd and LPS toxicity. Cd exposure also caused a marked increase in hepatic Zn levels, but LPS did not cause any changes in hepatic Zn or Cu content. In sharp contrast, both Zn and Cu contents were decreased in the kidneys by 16 and 36% in animals exposed to Cd or LPS. A correlation analysis of measured variables reveals that renal Cu contents were inversely associated with plasma nitrate concentrations while urinary Cu excretion on day 3 showed a strong positive correlation with both urinary nitrate and Cd excretions on the same day. A linear regression analysis shows 20% of the variation in urinary Cu excretion was associated with urinary Cd excretion on the same day. It is concluded that reductions in renal Cu contents caused by Cd or LPS administration may be a result of Cd and NO displacement of Cu previously bound to metallothionein.     

Cd, Cu, Zn, Se, and Metallothioneins in Two Amphibians, Necturus maculosus (Amphibia, Caudata) and Bufo bufo (Amphibia, Anura)

The accumulation of cadmium, its affinity for metallothioneins (MTs), and its relation to copper, zinc, and selenium were investigated in the experimental mudpuppy Necturus maculosus and the common toad Bufo bufo captured in nature. Specimens of N. maculosus were exposed to waterborne Cd (85???g/L) for up to 40?days. Exposure resulted in tissue-dependent accumulation of Cd in the order kidney, gills > intestine, liver, brain > pancreas, skin, spleen, and gonads. During the 40-day exposure, concentrations increased close to 1???g/g in kidneys and gills (0.64?C0.95 and 0.52?C0.76; n?=?4), whereas the levels stayed below 0.5 in liver (0.14?C0.29; n?=?4) and other organs. Cd exposure was accompanied by an increase of Zn and Cu in kidneys and Zn in skin, while a decrease of Cu was observed in muscles and skin. Cytosol metallothioneins (MTs) were detected as Cu,Zn?Cthioneins in liver and Zn,Cu?Cthioneins in gills and kidney, with the presence of Se in all cases. After exposure, Cd binding to MTs was clearly observed in cytosol of gills as Zn,Cu,Cd?Cthionein and in pellet extract of kidneys as Zn,Cu,Cd?Cthioneins. The results indicate low Cd storage in liver with almost undetectable Cd in liver MT fractions. In field trapped Bufo bufo (spring and autumn animals), Cd levels were followed in four organs and found to be in the order kidney > liver (0.56?C5.0???g/g >0.03?C0.72???g/g; n?=?11, spring and autumn animals), with no detectable Cd in muscle and skin. At the tissue level, high positive correlations between Cd, Cu, and Se were found in liver (all r?>?0.80; ???=?0.05, n?=?5), and between Cd and Se in kidney (r?=?0.76; n?=?5) of autumn animals, possibly connected with the storage of excess elements in biologically inert forms. In the liver of spring animals, having higher tissue level of Cd than autumn ones, part of the Cd was identified as Cu,Zn,Cd?Cthioneins with traces of Se. As both species are special in having liver Cu levels higher than Zn, the observed highly preferential Cd load in kidney seems reasonable. The relatively low Cd found in liver can be attributed to its excretion through bile and its inability to displace Cu from MTs. The associations of selenium observed with Cd and/or Cu (on the tissue and cell level) point to selenium involvement in the detoxification of excessive cadmium and copper through immobilization.     

Selenium,cadmium, zinc,and copper in human kidney cortices and post mortem indices of hypertension

Kidneys from 32 autopsied Caucasian human subjects aged 16–60 were frozen then lyophilized while the flasks were kept in insulating containers. (Subjects with evidence of extensive weight loss, chronic renal failure, or carcinoma were not included). Replicate samples of cortex were removed, weighed, and wet-ashed in HNO₃?HClO₄. Zn, Cd, and Cu were estimated by atomic absorption spectrophotometry with the 2261 Å line used for Cd background correction. Se was estimated by fluorescence with DAN in a Turner fluorimeter, but a #74 Kodak Wratten filter was added to minimize the 500 nm interference noted by E. Pickett (personal communication, 1980). Means and variability for the three elements in kidney cortex were similar to those in a North Carolina study as was Cd/(Cd+Zn)×100. Cortical Cd (P<0.05), Zn (P<0.10), and Cd/(Se·Zn) (P<0.05) increased with age, whereas Se showed no significant relationship with age. Age², nonlinear effects of age, had a slight influence upon Cu (P<0.05) only if data were not adjusted for gender. There was no influence of ageper se upon Cu with or without adjustment for gender. The scatter diagrams of element concentrations plotted vs age contained several provocative “outlier” values. A positive association of kidney cortex Cd concentration, or Cd/(Se ·Zn), with postmortem indices of hypertension existed only if age, gender, and age² were omitted from the multiple regression equation. This adjustment was not included in a similar study of North Carolina cases and appears to be the source of the major difference in their respective inferences drawn about the positive relationship of kidney cortex Cd with evidence of hypertension. This difference in statistical models does not however account for the failure of the West Virginia sample to indicate a protective role of kidney cortex Se suggested for the North Carolina subjects. Larger samples, drawn from regions differing in Se abundance, will be necessary to test the latter question adequately.     

Concentrations of heavy metals in vegetables between 2004 and 2018, and its impacts on human health in China

Abstract

Heavy metals in vegetables are of great concern worldwide due to their potential bioaccumulation in human. This review-based study researched the concentrations of heavy metals in vegetables from all provinces of China between 2004 and 2018, and assessed the health risk for the residents. The results displayed the highest Pb, Cd, Cu, and Zn concentrations in vegetables were 0.192?mg/kg (west area), 0.071?mg/kg (central area), 3.961?mg/kg (central area), and 10.545?mg/kg (central area), which were lower than the maximum allowable concentration. In the national scale, the weighted average level of heavy metals in vegetables was found to be in the order of Zn?>?Cu?>?Pb?>?Cd. The hazard index (HI) of each province showed that beside Anhui and Hunan province, residents in other provinces of China faced a low high risk of Pb, Cd, Cu, and Zn. However, people consuming vegetables faced a high risk of Pb, Cd, Cu, and Zn in Anhui and Hunan provinces. This research may provide insight into heavy metal accumulation in vegetables and forecast to residents to cope with these problems for improved human health.     

Cadmium accumulation, zinc status, and mineral bioavailability of growing rats fed diets high in zinc with increasing amounts of phytic acid

Five groups of individually housed albino rats (n=7, initial average weight=48 g) were fed diets based on egg albumen and cornstarch (basal diet 8.2 g Ca, 6.0 g P, 0.7 g Mg, 225 mg Zn, 150 mg Fe, 60 mg Mn, 8 mg Cu, and 5 mg Cd) over a 4-wk period. Group I (control) was fed the basal diet free of phytic acid (PA). In groups II, III, IV, and V, cornstarch was replaced by 3.5, 7.0, 10.5, and 14.0 g sodium phytate/kg diet, respectively. Daily gain, feed efficiency, Zn status (Zn in plasma, femur, testes, liver and kidneys, activity of the plasma alkaline phosphatase) and apparent absorption of Zn, Fe, Cu, and Mn remained unchanged by the different dietary treatments. PA decreased apparent Mg absorption significantly and apparent absorption of Ca in tendency. Increasing the amount of phytate caused a corresponding enhancement of amount of the digestible P. Cd accumulation in the liver was not significantly altered, and kidney Cd accumulation slightly increased owing to PA. In conclusion, it was shown that under conditions of high dietary Zn, PA had only little effect on the carryover of Cd in growing rats.     

Seasonal Variation of Metals in Seawater, Sediment, and Manila Clam Ruditapes philippinarum from China

Concentrations of trace metals (Cu, Pb, Zn, Cd, Cr, Hg, and As) were determined for the first time in seawater, sediment, and Manila clam from Deer Island, Liaoning Province, China. The seawater, sediment, and clam samples were collected seasonally at three clam farming sites around Deer Island during 2010–2011. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the seawater samples were 4.16, 0.72, 5.88, 0.45, 2.51, 0.03, and 1.02 μg/l, respectively. The seasonal variations of trace metals in seawater showed a significant difference in the concentrations of Cu, Pb, Zn, Hg, and As among seasons. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the sediment samples were 6.43, 13.80, 53.08, 1.10, 36.40, 0.05, and 4.78 mg/kg dry weight, respectively. Trace metal concentrations in sediment seasonally varied significantly except for Cd and Hg. The average concentrations of Cu, Pb, Zn, Cd, Cr, Hg, and As in the clam samples were 11.28, 0.61, 92.50, 0.58, 3.98, 0.03, and 1.98 mg/kg dry weight, respectively. Concentrations of Cu, Zn, Cd, Cr, and As in Manila clam showed marked seasonal fluctuations with significant difference. Cu and Zn were the metals with the highest mean biosediment accumulation factor values in Manila clam. Besides, significant correlations for the concentrations of Cu and Zn relative to their concentrations in sediment were also found. Such differences in regression analyzes may be explained by differential bioaccumulation of essential and xenobiotic metals. Concentrations of trace metals in Manila clam did not exceed the maximum established regulatory concentrations for human consumption. Moreover, the calculations revealed that the estimated daily intake values for the examined clam samples were below the internationally accepted dietary guidelines and the calculated hazard quotient values were well less than 1, thus strongly indicating that health risk associated with the intake studied metals through the consumption of Manila clam from Deer Island was absent.     

华南地区典型燃煤电厂周边土壤重金属分布、风险评估及来源分析

为了解华南地区典型燃煤电厂周边表层土壤重金属空间分布特征,对韶关市燃煤电厂周边20处农田表层土壤中7种重金属(镍(Ni)、铜(Cu)、锌(Zn)、镉(Cd)、铅(Pb)、铬(Cr)及砷(As))的总量进行检测,并分析了其相应的空间分布规律,同时评估了周边土壤重金属的生态风险并分析其来源。结果表明:该燃煤电厂周边土壤中重金属Ni、Cu、Zn、Cd、Pb、Cr及As的平均含量分别是17.79、19.59、159.08、3.14、111.01、96.61 mg/kg和21.48 mg/kg,Cd、Pb污染情况突出,重金属Zn、Cd、Pb、Cr的分布与盛行风向密切相关。综合污染指数法表明,Cd、Pb及Zn处于重污染状态;潜在生态风险指数法表明,Cd处于严重潜在生态风险状态;地累积指数法表明,Ni、Cu整体处于无污染状态,Cd整体处于高污染状态。多种统计方法表明,Zn、Cd、Pb及Cr受燃煤电厂影响明显,Cu、As的来源不仅受燃煤电厂等工业的影响,还与该地区农业灌溉用水密切相关,Ni的分布最为均匀,受自然因素影响明显。     

Lipid peroxidation assessed by serum thiobarbituric acid reactive substances in healthy subjects and in patients with pathologies known to affect trace element status

Serum thiobarbituric acid reactive substances (TBARS), Zn, Cu, and Se concentrations were determined in 47 healthy adults and in patients with diseases, such as renal in sufficiency, insulin-dependent diabetes mellitus, chronic pancreatitis, liver cirrhosis, or cancer, in order to clarify the relationship between this indicator of lipid peroxidation and antioxidative trace element status. TBARS levels were higher than control values in all pathological cases, except in cancer patients. Cu levels in patients highly correlated with ferroxidase ceruloplasmin activity (r=0.86), but were only statistically different from controls in diabetics. Zn levels were lower than normal in dialysis, liver cirrhosis, and cancer patients. Se levels were significantly decreased in all pathological cases. Half of the subjects with liver cirrhosis or renal insufficiency and 3/4 of chronic pancreatitis or cancer patients had an active inflammatory process. Despite intense modifications in determined indicators, no clear correlation could be demonstrated between the different parameters. Basic antioxidative trace element status and inflammation are therefore not major determinants of TBARS levels in normal and in pathological conditions, despite of the frequent association of low serum Zn and mainly low serum Se with high TBARS levels.     

Hepatic distribution of iron, copper, zinc and cadmium-containing proteins in normal and iron overload mice

Subcellular distribution of metal-containing proteins of Fe, Cu, Zn and Cd were determined in the liver samples of iron overload mice by size exclusion high performance liquid chromatography with on-line coupling to UV and inductively coupled plasma mass spectrometry. Collision cell techniques was used to remove polyatomic interferences for some elements, such as Fe. Comparative molecular weight (MW) information of the elemental fraction was obtained within a retention time of 40 min. Fe was present only in high-MW (HMW) protein; Cu, Zn and Cd were found in different MW proteins. It was also observed that these four elements studied showed predominant association with HMW fractions. Moreover, compared with the normal group, we found that the contents of these elements except Cu significantly increased and the distribution of some elements like Cd changed in iron overload mouse liver. It means that excessive iron accumulation in vivo may affect the metabolism of other element such as Zn and Cd.     

Screen of Chinese Weed Species for Cadmium Tolerance and Accumulation Characteristics

The cadmium (Cd) tolerance and metal-accumulation characteristics of 29 species (18 families) of weed were studied by using outdoor pot-culture experiments. The results of this screening showed that Bidens pilosa and Kalimeris integrifolia (both Asteraceae) expressed some properties that are characteristic of Cd hyperaccumulators. In 10 mg/kg Cd-spiked soil, they accumulated a good deal of Cd in shoots (28 and 25 mg/kg DW, respectively) with high Cd enrichment factors (EFs; concentration in plant/soil). Cd accumulations in shoots were greater than those in roots (translocation factor (TF) >1, concentration in shoot/root) and the shoot biomasses did not decreased significantly compared to the unspiked control. The other weed species showed little accumulation of Cd, Pb, Cu, or Zn. In a concentration-gradient experiment, the Cd accumulation potentials of B. pilosa and K. integrifolia were examined further. Cd concentrations in leaves of B. pilosa growing in soils spiked with 25, 50, and 100 mg/kg Cd were up to 145, 160, and 192 mg/kg, respectively, and the Cd content in stems in the 100 mg/kg Cd-spiked soil was 115 mg/kg, all greater than the 100 mg/kg notional criterion for Cd hyperaccumulation. The Cd EFs and TFs were all greater than 1. The shoot biomasses did not decrease significantly compared to the controls. B. pilosa was thus shown to have some characteristics of a true Cd hyperaccumulator plant.