Liver elemental content

The elemental homeostasis is the particularity of total homeostasis of organism, the alteration of the parameters of this system may result in pathological changes. The liver is the organ where the detoxication processes take place. The elemental content of the liver may reflect the pathological processes which occur not only in the liver but also in the whole organism. 

Figure 3 Identification of the elemental content of an inclusion in a pathological specimen. (A) An unstained transmission electron microscope image of a thin section from a liver biopsy N, nucleus M, mitochondria. The lysosomes contain electron-dense deposits. (B) An X-ray spectrum produced by focusing the electron beam onto the specimen shows the deposits contain iron. (C) A map of iron distribution in the specimen shows that the element is confined to areas containing the deposit.

Table 2.2 Comparison of present results with some reported elemental contents in human liver of normal subjects in different areas of the world (pg —g ) 2004 Springer-Verlag.

Copper is an essential trace element absorbed in the gut and transported to the liver bound to albumin. It is found in a variety of enzymes, including superoxide dismutase. In the bloodstream Cu is present mostly in ceruloplasmin. Tissues with a relatively high content of Cu are liver, heart, and brain. The RDA for Cu in normal, healthy adults is 0.9 mg day-1, but newborns usually have liver levels higher than those of adults. The concentration of Cu in mature milk ranges between 0.2 and 0.3 mg l-1 in colostrum it is higher (0.4-0.6 mg l-1), but decreases along the lactation period (see the Chapter 13 by de la Flor St Remy et al.). 

In past years, on line chromatographic coupling techniques such as HPLC and CE coupled to ICP-MS with the isotope dilution technique have been used for element quantification in speciation analysis. An interesting application of the isotope dilution technique in medical research was proposed recently by Prange and co-workers, who added highly enriched " S, Cu, Zn and Cd spikes to the interface of the CE-ICP-MS system. The authors separated isoforms of metallothionein (e.g., of rabbit liver) by capillary electrophoresis and quantified S, Cd, Cu and Zn concentrations in isoforms by ICP-SFMS using the isotope dilution technique. A new selenized yeast reference material (SELM-1) for methionine, selenomethionine (SeMet) and total selenium content has also certified by an intercomparison exercise. ... 

Liver portions (tip and mid-ventral blubber samples) of seals from the pack-ice of Queen Maud Land were analyzed for their contents in trace elements (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn) and chlorinated hydrocarbon residues (DDE, DDT, dieldrin, PCBs, TDE) (72). Samples were stored at -20°C pending analysis. The metals were quantified by AAS after digestion, as appropriate. The organic compounds were first extracted with hexane, cleaned-up and then assayed by gas-liquid chromatography with EC detection. Concentrations in the high pg g level... 

For some vitamins or trace elements, serum measurement is limited in value, especially in seriously ill patients. This is partly a result of the lack of correlation between the amount of nutrient in the plasma compartment with the amount within the intracellular compartment in most body tissue. For example, there may be substantial stores of particular vitamins or trace elements in individual tissue (e.g., vitamin A in the liver), but mobilization into the plasma is affected by the availability of the appropriate binding proteins or by metabolism. Also, there are differences in the content of individual vitamins or trace elements between tissues, and the serum concentration will not reflect these differences. Fur-tliermore, and particularly important, is the fact that the concentration in plasma can alter rapidly when an acute phase response (APR) to trauma or infection leads to redistribution of metals between body compartments there is increased synthesis of metallothionein, leading to the uptake of zinc into the fiver, and increased synthesis of ferritin causing uptake of iron. The result is a fall in plasma concentration of both zmc and iron. These changes in plasma concentration clearly do not reflect changes in whole body status. 

Although trace element abnormalities occur in chronic renal failure, few symptoms have been attributed to them in nondialyzed patients. In dialysis patients these disturbances appear to be qualitatively similar but more severe (T7). They have been extensively reviewed by Alfrey (A5). Total body zinc (except in erythrocytes), strontium, aluminum, and tin are generally increased, whereas total body rubidium is decreased. Iron stores tend to be increased in the spleen and liver in dialyzed patients, especially after ferrous sulfate therapy. Copper is increased in lung tissue and decreased in heart tissue and erythrocytes. Molybdenum and cadmium are decreased in renal tissue but increased in liver tissue of dialyzed and nondialyzed patients. Total body zinc content is significantly increased (A5), but hypozincemia, frequently observed in dialysis patients, has been blamed for taste impairment and impotence and there is conflicting evidence on whether zinc repletion corrects these abnormalities (K4, Ml2). Nickel is also increased in the serum of uremic patients, but this does not appear to be associated with a corresponding increase in tissues (S5). It cannot be concluded that trace element retention in renal failure is of no clinical importance, as shown by the problem of aluminum intoxication, to be discussed later. In addition, trace elements such as rubidium and bromine, which are rapidly depleted in uremic patients on maintenance dialysis (A5), may prove to be essential in normal metabolism. Thus the clinical importance of these element alterations remains unclear. 

Copper toxicity towards plants is less common than deficiency. This is in contrast to animals, where toxicity may be induced by an environmental excess of the element or with normal environmental concentrations in genetically susceptible individuals (Dawson and Price 1977). In the food chain, tolerant plant and invertebrates may accumulate copper and pose a certain risk for higher animals which consume them. Plants contain between 4 and 20 mg Cu kg dry weight, marine algae 2 to 68, fish 0.7 to 15, muscle of mammals about 10, and mammalian bones 1 to 26 (Bowen 1985). The total amount of copper in the adult human body is about 100 mg blood contains about 1 mg Cu Foods with a higher copper content include the parenchymatous internal organs of mammals, birds, and fishes especially liver, shellfish, cocoa, and red wine. The average daily copper consumption is about 0.8-1.6 mg... 

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