Cadmium body content

The body content of cadmium increases with age. In the newborn, the total body content is less that l xg, increasing to about 15-20 mg in cin adult human in the UK and Sweden. Cadmium enters the body mainly via the respiratory and gastrointestinal tracts. According to experimental data, after inhalation about 10-40% is absorbed. The absorption depends on the particle size and solubility, with higher values for small and highly soluble particles. ... 

Metallothioneins are a group of small proteins (about 6.5 kDa), found in the cytosol of cells, particularly of liver, kidney, and intestine. They have a high content of cysteine and can bind copper, zinc, cadmium, and mercury. The SH groups of cysteine are involved in binding the metals. Acute intake (eg, by injection) of copper and of certain other metals increases the amount (induction) of these proteins in tissues, as does administration of certain hormones or cytokines. These proteins may function to store the above metals in a nontoxic form and are involved in their overall metaboHsm in the body. Sequestration of copper also diminishes the amount of this metal available to generate free radicals. 

Pelgrom, S.M.G.J., L.P.M. Lamers, J.A.M. Garritsen, B.M. Pels, R.A.C. Lock, P.H.M. Balm, and S.E.W. Bonga. 1994. Interactions between copper and cadmium during single and combined exposure in juvenile tilapia Oreochromis mossambicus influence of feeding condition on whole body metal accumulation and the effect of the metals on tissue water and ion content. Aquat. Toxicol. 30 117-135. 

Cadmium shares chemical properties with zinc and mercury, but in contrast to mercury, it is incapable of environmental methylation, due to the instability of the monoalkyl derivate. Similarities and differences also exist in the metabolism of Zn, Cd, and Hg. Metallothioneins and other Cd-binding proteins hold or transport Cd, Zn, and Hg within the body. Metallothioneins are metal-binding proteins of relatively low molecular mass with a high content of cysteine residues that have a particular affinity for cadmium, as well as for zinc and copper, and can affect its toxicity. 

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. 

The mean cadmium content of unwashed hair was 1.423 0.508 and 1.559 1.135 pgg-1 for non-smokers and smokers, respectively270-272. About 60 papers273 - 324 which stress that the scalp hair is a valuable tissue recording the level and changes of many trace elements in the body have been reviewed269. 

The current PTWI is 7 pg kg body weight (WHO 2001). Particular risk groups can be characterized, namely of children smokers women with low iron stores consumers of food items with high cadmium content and extreme consumers of staple food items. At present, by using available data, it is not possible to characterize risk groups in detail, either at EU level or at Member State level. However, most Member States appear to have an average intake of cadmium which is lower than the WHO s PTWI (de Meeus et al. 2002). In Germany, one study indicated enhanced levels in an industrialized area (Wilhelm et al. 

Phosphorus fertilizers may contain impurities among those are some heavy metals that are of concern. In particular, cadmium (Cd) has received attention during the past few years. The level of cadmium content in fertilizers has been more or less arbitrarily limited to the concentration of 50 mg Cd/kg of P2O5 [7]. WHO has limited the daily intake of Cd to 1 microgram Ag of body weight per day [7]. The current average intake in Europe is lower than this limit [8]. 

In vivo mercury exposure does induce the synthesis of metallo-thionein in the kidney. The absolute amount of thionein bound mercury, however, usually is small for example, less than 2% of the total renal content at 24 hr after the injection of 0.5 mg Hg2+/kg body weight into the male rat (Webb and Magos, 1976). In contrast, at low-level cadmium exposure, most of the metal accumulated in the kidney is bound to metallothionein. The synthesis of this metalloprotein under these conditions parallels the renal uptake of cadmium until, at least, old age (Cain et al., unpublished). The critical renal concentration at which kidney dysfunction occurs at chronic exposure is high - about 200 yg Cd /g wet weight (Friberg et al., 1974), since only about 20% of this cadmium will be in the toxic non-thionein bound form. 

Contamination of the environment by the toxic elements increases their content in the organs and tissues of animals. Toxic elements enter the bodies of animals in particular by the oral route via consumed food. In human nutrition, the concentration of these elements in muscle and viscera of animals (farm as well as wild animals) is the most important factor. The content of lead and cadmium in the liver and kidneys of wild animals indicates the load of the contaminated animal food and habitat pollution level in which an animal lives. Under normal conditions, the content of lead and cadmium in meat is very low (thousandths of mg/kg), in contrast to the concentration in the kidney and Hver, which are sometimes up to 2-3 orders of magnitude higher. In these organs, lead and cadmium accumulate signihcantly. 

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