Concentrations Of Essential Metals Research Articles

Effect of chronic cadmium administration on liver and kidney concentrations of zinc, copper, iron, manganese, and chromium.

Chronic Cd exposure in animals brings about significant morphological and functional changes in both liver and kidney. Most studies of cadmium effects on essential metal tissue distribution involve large concentrations of either Cd or essential metals added to the diet. The effect of Cd ingestion on trace metal metabolism of animals consuming usual diets may be marked, as elements whose physical and chemical properties are enough alike...will act antagonistically to each other biologically. Therefore, the purpose of the present study was to observe the effects of a chronic low dose of Cd added to an otherwise normal diet on the liver and kidney accumulation of zinc, copper, iron, manganese and chromium in the mouse at different times after the cessation of cadmium ingestion.

Effect of cadmium on essential metal concentrations in testis, liver and kidney of five inbred strains of mice

To compare the organ injuries by cadmium administration among inbred strains of mice, CdCl 2 was injected subcutaneously into C3H/He, BALB/c, DBA/2, CBA/J and C57BL/6 strains at a dose of 30 μmol/kg body weight, and the changes of 6 essential metal [sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), iron (Fe) and zinc (Zn)] concentrations were determined at 6, 24 and 48 h. Testicular Cd concentrations at 6 h in DBA/2 and CBA/J were significantly higher than those in the other 3 strains. Marked alterations in testicular metal concentrations (increases in Na, Ca and Fe and decreases in K and Mg) were observed in the 2 strains. At 48 h, hepatic Cd concentration in BALB/c was decreased from the higher level at 24 h and an abrupt increase in renal Cd concentration was detected. Changes in hepatic essential metal concentrations at 48 h in BALB/c were in the same direction as those in the testis of DBA/2 and CBA/J. As a whole, C3H/He, BALB/c and C57BL/6 strains showed more remarkable alterations in hepatic essential metal concentrations, except Zn level, than DBA/2 and CBA/J which showed larger increases in Zn concentration (probably due to larger metallothionein induction). It was suggested from the data that C3H/He, BALB/c and C57BL/6 were strains sensitive to the hepatotoxicity of Cd and that DBA/2 and CBA/J were susceptible to the testicular toxicity of Cd.

Comparative metal analyses in amphipod crustaceans

Concentrations of Cu, Zn, Fe and Pb have been measured in amphipods (Crustacea:Amphipoda) from marine, littoral, semi-terrestrial and freshwater habitats in S. W Scotland, including amphipods expected to have high body metal loads. Metal concentrations (y) were affected greatly by body size (x) and could be modelled by the power function (y = a xb), with the smallest amphipods containing the highest concentrations. This finding cautions against the uncritical use of mean metal concentrations in assessments of heavy metal contamination using crustacean monitors. Data were transformed logarithmically for comparison by regression analysis, analysis of variance and analysis of covariance which compensated for the size effect. Essential metal concentrations are compared against theoretical estimates of metabolic requirements. The effects of seasonal changes and the presence of gut contents on metal concentrations have also been considered.

Trace element distribution within the tree phytomass and forest floor of a tolerant hardwood stand, Algoma, Ontario

An examination of tree phytomass and trace metal concentrations (w/w) and pools in the tree stratum and forest floor of a sugar maple-yellow birch forest was carried out at Turkey Lakes Watershed, Algoma District, Ontario. Estimated aboveground tree phytomass (167, 500 kg ha−1) was dominated by stemwood, branches > 2 cm, and stem bark. Highest trace metal concentrations were found in foliage (Cu, Fe, Mn, Ni) and stem bark (Cd, Pb, Zn). Concentrations of essential trace metals found in all sugar maple components followed the expected sequence of Mn>Fe>Zn>Cu. Lead and Ni concentations were always higher than those of Cd. Concentrations of essential elements in foliage and other components were comparable to those reported in the literature for other localities in North America. There was no indication that availability of essential trace elements (e.g., Cu) to vegetation had been increased as a result of increased atmospheric deposition. Lead, Ni and Cd levels in vegetation and forest floor were lower than those reported for similar forested areas of the northeastern United States.

Tissue metal concentrations in two crayfish species cohabiting a tennessee cave stream.

Concentrations of Cd, Cr, Cu, Fe, Mg, Mn, Pb, Zn, Ca and K were examined in tissues of the troglobitic (obligatory cave-dwelling) crayfish Orconectes australis australis and troglophilic (facultative cave-dwelling) species Cambarus tenebrosus. These two species cohabit a stream in Merrybranch Cave, located in rural White Co., Tennessee. Tissue concentrations of essential metals did not exhibit any trends between species. In contrast, Cd and Pb concentrations were found to be significantly greater in O. a. australis for almost all of the tissues analyzed. The higher Cd and Pb concentrations in O. a. australis are thought to be due to the increased longevity of this troglobitic species. Because of the toxicity of Cd and Pb, chronic exposure to relatively low concentrations of these metals could cause changes in mortality, fecundity or behavior in aquatic organisms possessing long life spans. The bioaccumulation of metals from low level, non-point sources is discussed in relation to life history strategies.

The effect of levodopa, lergotrile, and bromocriptine on brain iron, manganese, and copper.

Chronic administration of a levodopa-carbidopa combination, bromocriptine, or lergotrile produced alterations of essential metal concentrations in the guinea pig caudate nucleus, frontal cortex, and cerebellar hemisphere. All long-term treatment regimens resulted in significantly increased concentrations of manganese in all brain areas, and these same regimens resulted in almost universally decreased copper concentrations. Since the long-term administration of these dopamine agonists in man results in extrapyramidal dysfunction, these observations suggest that alterations of trace metal concentrations in the brain may be related to the chronic toxicity of these dopamine agonists.

REMOVAL OF TRACE METALS FROM MARINE CULTURE MEDIA

The sodium form of purified Chelex‐100 can be used to remove trace metals from artificial and natural seawater without altering the major cation‐anion composition or contributing organic toxicants or chelators. Specific contaminant trace metals, often present in artificial seawater at toxic levels, are reduced to levels that permit the growth of sensitive marine phytoplankton and the development of certain invertebrates from the egg through early larval stages. The concentrations of essential trace metals are reduced below the nutritional requirements of selected species of marine phytoplankton.

Determination of essential and toxic metals in meats, meat products and eggs by spectrophotometric method

The concentration of essential metals such as Fe, Cu, Mg, Co and Zn and toxic metals such as Pb, Cd, Cr, As and Ni were determined in a number of animal meats, organ meats, meat products, and eggs by using UV-visible and atomic absorption spectrophotometry (AAS). The essential metal estimation in the investigated samples indicated the following range of concentration: Fe: 11 - 623 mg kg-1, Cu: 1 - 165 mg kg-1, Mg: 16 - 1372 mg kg-1, Co: 0.01 - 48 mg kg-1, Zn: 15 - 295 mg kg-1. These concentrations of essential metals are in the range of human necessities. The concentrations of toxic metals in the same samples were: Pb: 0.03 - 43 mg kg-1, Cd: 0.01- 8 mg kg-1, Cr: 0.02 - 5 mg kg-1, As: 0.004 - 3 mg kg-1 and Ni: 0.03 - 41 mg kg-1. The concentration of arsenic in all samples was found negligible and this indicates that the investigated samples are safe from arsenic toxicity. The concentrations of other four toxic metals being very negligible in most of the samples indicate that these foodstuffs are reasonably safe from metal toxicity. However a few samples which exhibited higher concentrations of these metals above their tolerance limits are alarming for the public health and demand regular examination of these items before coming to the markets. The information obtained from the present investigation is expected to be useful to the general people of this region in selecting meats as their diets. Keywords: Meats; Organ meats; meat products; eggs; AAS; Heavy metals concentrations. DOI: http://dx.doi.org/10.3329/jbcs.v24i2.9705 Journal of Bangladesh Chemical Society, Vol. 24(2), 165-172, 2011

Metal toxicity in plants: How do metallophytes manage to grow?

Some of the metals (e.g. Cu, Mg, Mn etc.) are essential micronutrients of plants but other metals (e.g. Pb, Cr, Ni etc.) are non essential. Higher concentration of both essential and non essential metals are toxic to the plants. However, some plants called metallophytes, can grow in metal rich soil. Resistance to metal may involve exclusion from protoplast or detoxification and storage of metals in relatively inert sites such as vacuole. An understanding of genetic and physiological basis of the process involved in detoxification of metals is important in agriculture, afforestation etc. Cellular mechanisms of metal detoxification are briefly discussed.
 
 Himalayan Journal of Sciences 1(1): 51-54, 2003