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1.
K Kostial B Kargacin R Arezina M Landeka I Simonovi? 《Journal of hygiene, epidemiology, microbiology, and immunology》1991,35(4):337-350
The purpose of the present study was to obtain new data on the effect of age, route, dose and time of metal and chelating agent administration on the efficiency of chelation therapy. The experiments were performed on 1-2 and 6-week-old rats which received radioisotopes of metals--203Pb, 115 mCd, 203Hg and 141Ce intraperitoneally or orally. Chelating agents calcium ethylenediaminetetraacetate (CaEDTA), calcium and zinc diethylenetriaminepentaacetate (CaDTPA, ZnDTPA), 2,3-dimercapto-propane-sulfonate-1 (DMPS), dimercaptosuccinic acid (DMSA) and sodium N-(4-methoxybenzyl)-D-glucamine dithiocarbamate monohydrate (MeOBDCG) were administered twice by intraperitoneal or oral administration as early (immediately and 24 hr after metals) or delayed treatment (24 and 48 or 48 and 72 hr after metals). The animals were killed six days after metal administration and the retention was determined in the whole body, carcass and gut. After intraperitoneal administration of metals and chelating agents chelation therapy had much lower efficacy in younger than older animals. After ingestion of metals oral chelation therapy was more effective in younger than older animals. In suckling rats the treatment effectively reduced metal retention and this was mostly due to decrease in gut retention. This treatment in sucklings was also very effective in condition of late administration. In older rats early oral DMPS treatment after 203Hg ingestion is contraindicated since it increases significantly mercury retention while DMSA and ZnDTPA treatments reduced mercury retention. Delayed oral treatment with ZnDTPA and DMSA caused increased cadmium retention in older rats and decreased retention in sucklings. Opposite to results with CaDTPA, MeOBDCG was effective in reducing cadmium retention also when given as delayed treatment.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
2.
The metabolism of203Hg-labeled methylmercury chloride (MeHg) has been studied in rabbits and hamsters. Rabbits were administered 1.6 μmol MeHgCl/kg
bw intravenously, and hamsters 40 μmol/kg bw orally. Urine and feces were collected daily and groups of four animals killed
after 1 h, 1 d, or 7 d. The concentration of203Hg in blood, liver, kidney, spleen, lung, heart, and brain was determined by gamma counting.
In both animal species, the clearance of203Hg in the brain was slower than in other tissues. In the rabbits the brain203Hg concentration increased during the whole experimental period. Rabbits excreted203Hg primarily in feces (about 20% of the dose within 1 wk), and much less in urine (<2%). In contrast, hamsters very efficiently
excreted203Hg in urine (50% in 1 wk). The fecal excretion was similar to that of the rabbits. Separation of inorganic Hg and MeHg in
urine from hamsters by ion exchange chromatography showed that about 90% of the urinary203Hg was excreted as MeHg. 相似文献
3.
B Kargacin K Kostial M Landeka 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1983,44(4):363-366
The influence of age on the effectiveness of chelation treatment in reducing retention of radioactive cerium was studied in two- and six-week-old albino rats. 141Ce was administered intraperitoneally, followed immediately and after 24 and 48 hours by intraperitoneal administration of the tri-sodium calcium salt of diethylenetriaminepentaacetic acid--Na3(CaDTPA) at 380 mumol/kg body weight. The whole-body retention was determined 2, 4 and 6 days after radiocerium administration, when the animals were killed and the organ retention was determined. The chelation therapy significantly reduced the whole-body retention of radiocerium. This treatment was however twice as effective in older as in younger animals. 相似文献
4.
《Animal reproduction science》1987,13(2):143-155
Dietary selenium supplementation for rats resulted in a greater deposition of 109Cd in testis, but caused decreased deposition of the isotope in seminal vesicles, epididymis and prostate gland. In contrast, dietary selenium caused increased deposition of 203Hg in seminal vesicles and prostate gland but drastically reduced the levels of this radioisotope in testis and epididymis. Selenium diverted the binding of 109Cd in cytosols in testis, seminal vesicles, epididymis and prostate gland, but had minimal effects on the binding of 203Hg in these reproductive organs. Selenium deficiency caused increased excretion of 109Cd in feces and urine, and increased excretion of 203Hg in urine of rats. The biological half-lives of the two radioisotopes in the −Se and +Se rats were calculated to be, respectively, 202 and 219 days for 109Cd, and 2 and 6 days for 203Hg. 相似文献
5.
We tested the effect of cadmium (25, 130 μg Cd g−1), administered via Chinese cabbage (Brassica chinensis L.) as food on life-history parameters and gut microflora of tritonymphs and adults of the oribatid mite, Archegozetes
longisetosus Aoki. Both concentrations of Cd had an adverse effect on offspring mortality, and the higher concentration also reduced female
fecundity, as well as the number of bacteria, fungi and actinomycetes, and it changed the community structure of bacteria;
the proportion of gram-negative bacteria increased while that of gram-positive bacteria declined. Interestingly, at the lower
Cd concentration microflora was more abundant and diverse than in the control group, especially in the tritonymphs, although
the mean activity of gut microflora was reduced. The higher Cd concentration reduced microflora activity both in the tritonymphs
and adults. 相似文献
6.
Behavior of neutron-activated uranium dioxide dust particles in the gastrointestinal tract of the rat 总被引:1,自引:0,他引:1
The behavior of neutron-irradiated, simulated Chernobyl UO2 particles containing 141Ce, 144Ce, 95Zr, 95Nb, and 103Ru in the gastrointestinal tract was investigated to obtain basic information for dosimetric and risk analyses of nuclear accidents. After the UO2 particles were administered to rats intragastrically, the distribution and retention of specific radionuclides were studied by using whole-body autoradiography and gamma-spectrometric analysis of tissues. None of the radionuclides were detected in liver, kidney, muscle, bone, brain, blood, and urine. Approximately 98% of the total administered radioactivity was excreted in feces within 3 days. A two times greater intestinal retention (about 6%) of 95Nb than for the other radionuclides was observed 1 day after administration. The results indicate that this kind of relatively insoluble particulate material is not absorbed or retained significantly in the epithelial cells of the intestinal wall. Fallout particles containing high-energy beta sources, 106Ru and 144Ce, result in a very high radiation dose (up to several Gy/day) in the vicinity of a hot particle. Niobium-95 with low average beta energy (0.043 MeV (100%)) does not increase the total dose to the GI tract significantly despite its longer retention in the intestine. Evaluation of the biological effects of these particles in the GI tract by using a dosimetric model based on uniform distribution of activity may be misleading. 相似文献
7.
Radivoj Arežina Biserka Kargačin Krista Kostial Mark M. Jones Pramod K. Singh 《Biological trace element research》1993,37(2-3):151-156
The efficiency of chelating agents to remove aged intracellular deposits of cadmium in young and older rats was studied. The
administration of the chelating agent sodiumN-(4-methoxybenzyl)-D-glucamine-N-carbodithioate monohydrate (MeOBDCG) 2 wk after a single intraperitoneal 115m Cd administration reduced the whole body, liver,
and kidney retention in suckling rats to about 63, 42, and 71 percent and in older rats to 39, 17 and 76 percent of values
obtained in respective controls. Chelation therapy was generally more effective in older than younger rats and the age-related
effect was most pronounced in the liver. These results indicate that specific features of young organisms may significantly
alter the effect of chelation treatment. 相似文献
8.
The extent of contamination of soils by toxic heavy metals not only depends on the rate of loading of the metal but also on the nature of the adsorbing surfaces, the degree of alkalinity or acidity of the soil and the presence of aqueous complexant ligands. This work reports on the role of pH on the retention of Cd, Hg, Pb and Zn by two soils and on the influence of the chloride, Cl‐, ion on the chemical speciation and retention of the four metals. Batch adsorption experiments were conducted from pH 3 to 7 in the presence of either 0.1 M LiCl or LiClO4. The results of the study showed that high concentrations of Cl‐ ions can greatly decrease the retention of Hg and have an increasingly lesser effect on Cd, Pb and Zn retention. The effect of the Cl‐ons was directly related to the metal‐Cl formation constants. The results of computer modeling of Cd and Hg retention by goethite and humic acid fractions indicated the relative importance of aqueous vs. surface complexation on metal retention. For organic surfaces, which do not form ternary surface complexes, the presence of aqueous complexant ligands should always decrease the adsorption of the metal. For mineral surfaces, which do form ternary surface complexes, there may be increased or decreased metal retention depending on the formation constant of the aqueous metal‐ligand species, the intrinsic complexation constants for the various binary and ternary complexes of the metal and the concentration of the complexant ligand. Thus for Hg, which forms very strong aqueous species with Cl‐ ions, reduced adsorption on goethite was predicted in the presence of 0.1 M LiCl, while enhanced adsorption was predicted for Cd and Pb. The results suggest caution in the disposal of Cl‐containing wastes onto metal‐contaminated soils. The deleterious effects of Cl‐ ion addition would be greatest for soils with relatively high organic matter contents and low contents of hydrous ferric oxides. 相似文献
9.
Water pollution by toxic heavy metals is a burning environmental problem and has presented a challenge to humans. Removal
of heavy metals using non-living biomass of seaweeds could be a potential solution to this problem. In the present investigation,
biomass of three color forms of Kappaphycus alvarezii, viz. brown, green and pale yellow, were studied in the laboratory for their heavy metal chelating capacity using cadmium,
cobalt, chromium and copper. Amongst the four concentrations used (25, 50, 75 and 100 mg L−1) maximum chelation of Cd, Co and Cu was recorded at 25 mg L−1 concentration. The highest amount of Cr was chelated at 100 mg L−1 by all the three color forms. The pale yellow form showed maximum chelation for all four metals studied. Further, chelation
in all the color forms was found to be: Cd 5.37 ± 0.59–15.84 ± 0.32 %, Co 21.19 ± 0.13–32.32 ± 0.62 %, Cr 65.38 ± 0.27–88.09 ± 0.51
% and Cu 59.53 ± 0.37–90.28 ± 0.89 %. All the three color forms of K. alvarezii serve as an excellent biodetoxifier as they all chelated considerable amounts of heavy metals. 相似文献
10.
In order to test the effectiveness of complexing therapy on methyl mercury induced neurotoxicity, female rats were treated for five days with either 2,3-dimercaptopropanol (BAL) or D-penicillamine (DPA) beginning 1 or 12 days after the final dose of methyl mercury hydroxide (MMOH). MMOH was administered orally at a dose of 13.3 mg/kg once each day for 3 successive days. BAL, dissolved in peanut oil, was administered sc in a dose of 30 mg/kg twice each treatment day. DPA was dissolved in water and administered sc in a dose of 1200 mg/kg once each treatment day. Therapy begun 1 day after the last MMOH administration was prior to the appearance of toxic signs but therapy begun 12 days later was after signs had developed. The ability of BAL or DPA therapy to alter the distribution of radio-labelled (203Hg) MMOH was determined. Both DPA and BAL significantly reduced tissue concentrations of mercury when administered beginning 1 day after MMOH, but only DPA was effective in removing mercury from tissues when treatment was begun 12 days after the last dose of MMOH. In a separate experiment when either BAL or DPA therapy was initiated as above 1 day after the last dose of MMOH, the appearance of neurological signs of toxicity was prevented and weight loss was reversed. When therapy was initiated the twelfh day after the last MMOH dose, neither BAL nor DPA was effective in reversing either neurotoxic signs or weight loss. Therefore, therapy is ineffective in reversing neurological signs if it is delayed too long after MMOH administration, even though it is effective in reducing tissue mercury levels. 相似文献
11.
K Kostial B Kargacin M Landeka 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1987,51(1):139-145
The influence of diet or its ingredients on 141Ce absorption and retention was investigated in six-day-old rats. Animals were fed over 8h with cow's milk, rat diet or a mixture of rat diet ingredients (fish meal, sunflower meal, alfalfa, cane molasses and premix) labelled with 141Ce. Whole-body radioactivity was determined in a double crystal scintillation counter every 24 h over a six-day period. Gut, liver, kidney and femur retention and cerium distribution in the gut was determined at the end of the experiment. Compared to milk diet, administration of rat diet or ingredients caused respectively 3 and 7.5 times lower whole body retention. Carcass retention was reduced by rat diet or ingredients 2-3 times and intestinal retention 3 and 8 times respectively. Irrespective of the dietary treatment the main site of cerium intestinal retention was the ileum. Our present results indicate that some compounds of rat diet might be considered as a means of reducing cerium absorption and intestinal retention in the very young. 相似文献
12.
The different effects of Ce3+, Cd2+, and Hg2+ on the activities and secondary structure of trypsin were studied. The results showed that trypsin activity was increased
substantially by Ce3+ in 0.5–5 μmol/L concentration, but the activity was decreased significantly by Cd2+ or Hg2+ in 0.5–5 μmol/L concentration. The ultraviolet-visible spectrum of trypsin with 4 μmol/L Ce3+ treatment was the same as that of the control, but the 232-nm characteristic peak of trypsin with 4 μmol/L Cd2+ or Hg2+ treatment was blue-shifted and the peak intensity weakened. The circular dichroism (CD) spectrum of trypsin with 4 μmol/L
Ce3+ treatment was similar to that of the control. The secondary structure of trypsin did not change with Ce3+ treatment. However, the CD spectrum of trypsin with 4 μmol/L Cd2+ or Hg2+ treatment was different from that of the control and Ce3+ treatment. The secondary structure of trypsin with Cd2+ or Hg2+ treatment changed greatly; for example, the α-helix and β-sheet contents were reduced significantly, the β-turn was enhanced
greatly, and the random coil contents increased or decreased. 相似文献
13.
An existing radiochemical NAA procedure for Cd, Co, and Cu was improved to allow determination of individual radiochemical
yields by the radioisotopic tracer technique, thus eliminating errors owing to variable recovery.109Cd was used as tracer for Cd determination via115Cd/115mIn,57Co for Co via60Co, and potentially for Ni via58Co, whereas as a novelty67Cu, produced by reactor irradiation of ZnO of natural isotopic composition (by the67Zn [n,p]67Cu reaction) was used for Cu via the indicator nuclide64Cu. The simple production and purification of67Cu by anion exchange is described. Results for biological RMs are given and discussed. 相似文献
14.
Summary The effect of Ca on the absorption and translocation of Mn, Zn and Cd in excised barley roots was studied using a multi-compartment
transport box technique. A radioisotope (54Mn,65Zn or115mCd)-labelled test solution was supplied to the apexes of excised roots and the distribution pattern in the roots was examined
in the absence or presence of Ca. Results obtained were as follows.
Addition of Ca to the test solution reduced the absorption of Mn and inhibited drastically its translocation in excised roots.
With increasing concentrations of Ca in test solutions, its inhibitory effects on the absorption and translocation of Mn became
severe.
Similar results were observed for the absorption and translocation of Zn. Ca in the test solution decreased the absorption
and inhibited drastically the translocation of Zn; as in the case of Mn, higher concentrations of Ca had severe effects on
these functions.
It was also evident that the addition of Ca to the test solution reduced the absorption of Cd at all levels of Cd concentration
(1, 10, and 100 μM). Cd absorption decreased with increasing concentrations of Ca in the test solution. However, Ca accelerated the translocation
of Cd in excised roots supplied with test solutions containing up to 10μM Cd. At 100μM Cd, addition of Ca caused a negligibly small acceleration of Cd translocation.
The accelerating effect of Ca on Cd translocation, especially “xylem exudation”, decreased markedly with the addition of 2,4-dinitrophenol,
but not with the addition of chloramphenicol or p-chloromercuribenzene sulphonic acid. When barley plants were supplied with
only CaSO4 during the entire growing period, that is, plants were not supplied with nutrient solution on the last day of this period,
Ca had no accelerating effect on Cd translocation in excised roots. 相似文献
15.
We determined the inventories of four anthropogenic trace elements, Pb, Zn, As, and Cd, and two radionuclides, 137Cs and excess 210Pb, in sediment cores collected from eight remote lakes in the Adirondack region of the northeastern United States. The inventories of all six substances vary considerably among the sediment cores, although the lakes and their associated catchments must have received similar cumulative per unit area atmospheric inputs of these substances. These variations are highly correlated, indicating that the trace elements and radionuclides are affected in a coherent way by the processes controlling their deposition to the sediments of these lakes. Assuming that the anthropogenic trace element inventories in each sediment core are enhanced or depleted relative to cumulative atmospheric deposition to the extent indicated by the sediment core inventories of either 137Cs or excess 210Pb, we produced estimates of the cumulative atmospheric inputs of the four anthropogenic trace elements to this region. Comparison of the excess 210Pb normalized anthropogenic Pb, Zn, Cd inventories of the Adirondack sediment cores with excess 210Pb normalized inventories of the same substances in a group of South Central Ontario lakes suggests that the Adirondack region has received greater cumulative anthropogenic inputs of Pb, Zn and Cd by a factor of 1.6, 4.5, and 2.9, respectively. 相似文献
16.
P. De Clercq E. Viuela G. Smagghe D. Degheele 《Entomologia Experimentalis et Applicata》1995,76(2):189-194
Transport and retention of the insect growth regulators (IGRs) diflubenzuron and pyriproxyfen in larvae of the beet armywormSpodoptera exigua (Hübner) and in nymphs of the predatory bugPodisus maculiventris (Say) were investigated. In a first experiment, the retention of orally administered [14C]radiolabeled isotopes of both compounds in fifth-instar larvae of the beet armyworm was studied. Rate of excretion of both
IGRs inS. exigua caterpillars was high, with a 50% excretion time of approximately 6 h after intake. In a second experiment, the transport
of the compounds from prey to predator and their retention inside the predator were studied. Fifthinstar nymphs ofP. maculiventris were allowed to feed on caterpillars that had been given contaminated food. For both diflubenzuron and pyriproxyfen, more
than 80% of the amount of radiolabel applied was recovered in consumed prey. Low levels of radioactivity (c. 3% of the applied amount of radiolabel) were also found in the fluid regurgitated by the prey larvae when attacked by the
predatory bugs. Relatively small amounts of radiolabel (c. 8 and 15% of the amount orally applied to the prey for diflubenzuron and pyriproxyfen, respectively) were ingested byP. maculiventris nymphs when feeding on beet armyworm caterpillars. The data suggest that the predators did not use gut content as food. The
pattern of excretion in nymphs ofP. maculiventris differed between compounds. For diflubenzuron, there was a drastic decrease of radioactivity inside the predator body of
around 40% within the first 6 h and then the level of retained radiolabel remained stable at 3–4% up to 72 h. For pyriproxyfen,
a slow decrease of radioactivity inside the body was observed and at 72 h only 2% of the applied quantity was detected. Results
of this study are discussed in relation to the findings from previous studies on the toxicity of both IGRs toP. maculiventris. 相似文献
17.
Stress Responses of Zea mays to Cadmium and Mercury 总被引:2,自引:1,他引:1
Rubén Rellán-Álvarez Cristina Ortega-Villasante Ana Álvarez-Fernández Francisca F. del Campo Luis E. Hernández 《Plant and Soil》2006,279(1-2):41-50
A hydroponic experiment was carried out to characterize the oxidative stress responses of maize seedlings (Zea mays L. cv. Dekalb DK604) to cadmium (Cd) and mercury (Hg). Plants were grown hydroponically for 7 days in a nutrient solution
supplemented with several concentrations of Cd and Hg: 0.0 (control), 6 or 30 μM. Growth was inhibited by both metals. The
effect was more severe in plants exposed to Hg. Oxidative stress was caused by the exposure to the metals, as quantified by
malondialdehyde and carbonyl accumulation, by-products of lipid peroxidation and protein oxidation, respectively. The activity
of ascorbate peroxidase (APX) and superoxide dismutase (SOD), enzymes involved in the scavenging of reactive oxygen species,
were measured upon metal treatment. We found an activation of a cytosolic APX isoform, as identified by using a specific polyclonal
antiserum. However, there were negligible changes in SOD activity. Analysis of thiol-peptides revealed that at 6 μM Cd a remarkable
increase in root reduced glutathione (GSH) content occurred, and little effect on the relative content of oxidised glutathione
(GSSG) was observed. However, at 30 μM Cd and in plants exposed to 6 and 30 μM of Hg, GSH root content either remained stable
or decreased significantly, while the proportion of GSSG increased. Moreover, only Cd was able to induce accumulation of phytochelatins
at both assayed concentrations. Apparently, Hg was more toxic than Cd, as inferred from the magnitude of the changes found
in the physiological parameters tested. 相似文献
18.
Huang L Yu X Zhang J Liu X Zhang Y Jiao X Yu X 《Biological trace element research》2012,146(2):154-159
Wilson disease is an inherited autosomal recessive disorder causing copper accumulation and consequent toxicity. d-Penicillamine, a potent metal chelator, is an important therapy for Wilson disease. To investigate the changes of metal elements
under the treatment of d-penicillamine, we determined the levels of Cu, Zn, Mg, Ca, Fe, Se, Mn, Pb, Hg, Cd, As, Tl, and Al by ICP-MS in 24-h urine
of 115 Wilson disease patients who had received treatment with d-penicillamine for 1 month to 22 years at maintenance doses, as well as 115 age-matched, healthy controls. The levels of Cu,
Mg, Ca, Zn, Hg, Pb, Tl, Cd, and Mn in the 24-h urine of the cases were significantly higher than those of the controls (P < 0.05), and the observed increases in the levels of Mg, Ca, and Zn were directly correlated with the treatment duration
with Pearson Correlation Coefficient (R) of 0.356 (Mg), 0.329 (Ca), and 0.313 (Zn), respectively (P < 0.05). On the other hand, the levels of Al and As in the 24-h urine were lower than those of the controls (P < 0.05) and were negatively correlated with the treatment time with R of −0.337 (Al) and −0.398 (As), respectively, (P < 0.05). Thus, this study indicates that the levels of metal elements may be altered in patients with Wilson disease under
the treatment of d-penicillamine. 相似文献
19.
To further examine the interrelationships between manganese and iron absorption, the mucosal uptake, initial rate of loss,
wholebody retention, and tissue distribution of an orally administered 54Mn radiotracer were compared between normal and β2-microglobulin knockout [β2m(-/-)] mice. These mutant mice are commonly used as a model for the study of human hemochromatosis, a hereditary ironoverload
disease. Initial uptake of 54Mn by the intestinal mucosa, the liver, and the brain was not different between the two strains. The mutant mice had much
higher concentrations of nonheme and total iron in the liver, but hepatic manganese, copper, magnesium, and zinc concentrations
were similar between the two strains. In summary, the mucosal uptake and whole-body retention of manganese and tissue manganese
concentrations were not altered in β2m(-/-) mice; this suggests that normal homeostasis of manganese is not affected by the altered HFE protein-β2m complex in these mice.
Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the US Department
of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable. The US Department
of Agriculture, Agricultural Research Service, Northern Plains Area, is an equal opportunity/affirmative action employer and
all agency services are available without discrimination. 相似文献
20.
Anders Wicklund Glynn Nils-Gunnar Ilbäck Dagmar Brabencova Lena Carlsson Ella-Cari Enqvist Elvy Netzel Agneta Oskarsson 《Biological trace element research》1993,39(1):91-107
To study the effects of long-term selenium supplementation on absorption, distribution, and elimination of methylmercury (MeHg) in mice, three groups of male mice (Balb/c CA) were exposed for 7 wk to 0, 0.6, and 3 ppm sodium selenite in tap water. They were then given a single oral dose of Me203Hg (2 μmol/kg) by gastric intubation, and elimination of203Hg was followed by whole-body counting for 49 d at the same Se exposure as previously. Twenty-four hours and 49 d after dosage, 6–7 animals/group were sampled for analysis of203Hg distribution in the body. Glutathione peroxidase (GSH-PX) activity in blood and selenium levels in the liver were used as measures of selenium status. Gastrointestinal absorption of Me203Hg was not influenced by the Se status of the animals. Selenium supplementation of MeHg-exposed mice caused an enhanced whole-body elimination of Hg, but selenium-supplemented animals did not have lower Hg levels in the brain and kidney than nonsupplemented animals. The effect of selenium on the accumulation, of Hg in the brain was dose-dependent, a high dose (3 ppm Se) causing a higher initial accumulation of Hg. The intracellular distribution of203Hg in the liver and kidney was not affected by Se. The results indicate that selenium treatment of MeHg-exposed mice may have a positive effection the health of the animals by decreasing the total body burden of MeHg. 相似文献