Cadmium metabolism

Nordberg GF. Cadmium metabolism and toxicity. Environ Physiol Biochem 1972 2 7-36. 

Kjellstrom T, Nordberg GF. A kinetic model of cadmium metabolism in the human being. Environ Res 1978 16 248-269. 

Kjellstrom T, Nordberg GF. Kinetic model of cadmium metabolism. In Cadmium and health a toxicological and epidemiological appraisal. Friberg L, Elinder C-G, Kjellstrom T, Nordberg GF (editors). CRC Press, Boca Raton, Florida 1985 p. 179-197. 

Saint Remy A, Roels H, Rondia D, Sartor F and Tkijs L (1991) Effects of exposure to cadmium metabolism a population study. Br J Ind Med 48 710-714. 

Figure 13 Hypothetical model of cadmium metabolism in a marine diatom showing the buffering of Cd by PC binding and its use in periplasmic and cytoplasmic carbonic anhy-drases as part of C4 metabolism.

Fox MRS, Jacobs RM, Jones AOL, Fry BE Jr, Stone CL (1980) Effects of vitamin C and iron on cadmium metabolism. Ann. New York Acad. Sci. 335 249-261 Fox MRS, Tao S-H, Stone CL (1981) Increased cadmium in tissues with zinc, iron and copper deficiencies. Fed. Proc. 40 886... 

Hsu FS, Krook L, Pond WG, Duncan JR (1975) Interaction of dietary calcium with toxic levels of lead and zinc in pigs. J. Nutr. 105 112-118 Jacobs, RM, Fox MRS, Jones AOL, Hamilton RP, Lener J (1977) Cadmium metabolism Individual effects of zinc, copper, and manganese. Fed. Proc. 36 1152 Johnson NE, Tenuta K (1979) Diets and lead blood levels of children who practice pica. Environ. Res. 18 369-376... 

Selye H, Tuchweber B, Bertok L (1966) Effects of lead acetate on susceptibility of rats to bacterial endotoxins. Bacteriol. 91 884 Suzuki Y (1980) Cadmium metabolism and toxicity in rats after long-term subcutaneous administration. J. Toxicol. Environ. Hlth. 6 469-482 Vos JG (1977) Immune suppression as related to toxicology CRC. Grit. Rev. Toxicol. 67-101... 

Kello D, Kostial K (1977) Influence of age and milk diet on cadmium absorption from the gut. Toxicol. Appl. Pharmacol. 40 277-282 Kjellstrom T (1979) Exposure and accumulation of cadmium in populations from Japan, the United States and Sweden. Environ. Health Perspect. 28 169-197 Kjellstrom T, Nordberg GF (1978) A kinetic model of cadmium metabolism in the human being. Environ. Res. 16 248-269... 

Zinc and cadmium have an oxidation number of +2 in all their compounds. Zinc is an essential element for human health. It is present in many enzymes and plays a role in the expression of DNA and in growth. Zinc is toxic only in very-high amounts. However, cadmium is a deadly poison that disrupts metabolism by-substituting for other essential metals in the body such as zinc and calcium, leading to soft bones and to kidney and lung disorders. 

In mammals, as in yeast, several different metallothionein isoforms are known, each with a particular tissue distribution (Vasak and Hasler, 2000). Their synthesis is regulated at the level of transcription not only by copper (as well as the other divalent metal ions cadmium, mercury and zinc) but also by hormones, notably steroid hormones, that affect cellular differentiation. Intracellular copper accumulates in metallothionein in copper overload diseases, such as Wilson s disease, forming two distinct molecular forms one with 12 Cu(I) equivalents bound, in which all 20 thiolate ligands of the protein participate in metal binding the other with eight Cu(I)/ metallothionein a molecules, with between 12-14 cysteines involved in Cu(I) coordination (Pountney et ah, 1994). Although the role of specific metallothionein isoforms in zinc homeostasis and apoptosis is established, its primary function in copper metabolism remains enigmatic (Vasak and Hasler, 2000). 

Further work at EniTecnologies was conducted with Rhodococcus strains. Rhodococ-cus was selected for its metabolical versatility, easy availability in soils and water, and remarkable solvent tolerance. Its capabilities for catalyzing diverse transformation reactions of crude oils, such as sulfur removal, alkanes and aromatics oxidation and catabolism caught their attention. Hence, genetic tools for the engineering of Rhodococcus strains have been applied to improve its biotransformation performance and its tolerance to certain common contaminants of the crude oil, such as cadmium. The development of active biomolecules led to the isolation and characterization of plasmid vectors and promoters. Strains have been constructed in which the careful over-expression of selected components of the desulfurization pathway leads to the enhancement of the sulfur removal activity in model systems. Rhodococcus, Gordona, and Nocardia were transformed in this way trying to improve their catalytic performance in BDS. In a... 

Devi, V.U. 1996. Bioaccumulation and metabolic effects of cadmium on marine fouling dressinid bivalve, Mytilopsis sallei (Rccluz). Arch. Environ. Contam. Toxicol. 31 47-53. 

Ricard, A.C., C. Daniel, P. Anderson, and A. Hontela. 1998. Effects of subchronic exposure to cadmium chloride on endocrine and metabolic functions in rainbow trout Oncorhynchus mykiss. Arch. Environ. Contam. Toxicol. 34 377-381. 

Shore, R.F., D.G. Myhill, E.J. Routledge, and A. Wilby. 1995. Impact of an environmentally-realistic intake of cadmium on calcium, magnesium, and phosphate metabolism in bank voles, Clethrionomys glareolus. Arch. Environ. Contam. Toxicol. 29 180-186. 

Siewicki, T.C., J.E. Balthrop, and J.S. Sydlowski. 1983. Iron metabolism of mice fed low levels of physiologically bound cadmium in oyster or cadmium chloride. Jour. Nutr. 113 1140-1149. 

Chromium has proved effective in counteracting the deleterious effects of cadmium in rats and of vanadium in chickens. High mortality rates and testicular atrophy occurred in rats subjected to an intraperitoneal injection of cadmium salts however, pretreatment with chromium ameliorated these effects (Stacey et al. 1983). The Cr-Cd relationship is not simple. In some cases, cadmium is known to suppress adverse effects induced in Chinese hamster (Cricetus spp.) ovary cells by Cr (Shimada et al. 1998). In southwestern Sweden, there was an 80% decline in chromium burdens in liver of the moose (Alces alces) between 1982 and 1992 from 0.21 to 0.07 mg Cr/kg FW (Frank et al. 1994). During this same period in this locale, moose experienced an unknown disease caused by a secondary copper deficiency due to elevated molybdenum levels as well as chromium deficiency and trace element imbalance (Frank et al. 1994). In chickens (Gallus sp.), 10 mg/kg of dietary chromium counteracted adverse effects on albumin metabolism and egg shell quality induced by 10 mg/kg of vanadium salts (Jensen and Maurice 1980). Additional research on the beneficial aspects of chromium in living resources appears warranted, especially where the organism is subjected to complex mixtures containing chromium and other potentially toxic heavy metals. 

Raj, A.I.M. and P.S. Hameed. 1991. Effect of copper, cadmium and mercury on metabolism of the freshwater mussel Lamellidens marginalis (Lamarck). Jour. Environ. Biol. 12 131-135. 

Reichert, W.L., D.A. Federighi, and D.C. Malins. 1979. Uptake and metabolism of lead and cadmium in coho salmon (Oncorhynchus kisutch). Comp. Biochem. Physiol. 63C 229-234. 

Voogt, P.A., P.J.D. Besten, G.C.M. Kusters, and M.W.J. Messing. 1987. Effects of cadmium and zinc on steroid metabolism and steroid level in the sea star Asterias rubens L. Comp. Biochem. Physiol. 86C 83-89. 

Cadmium (soft, Cd2+) Renal toxicity Blocks sulfhydryl groups in enzymes and competes with zinc. Stimulates metallothionein synthesis and interferes with Cu(II) and Zn(II) metabolism. 

Metals are extremely important not only for chemical reactions but also for the health and welfare of plants and animals. Some examples of metals required for good nutrition, even in trace amounts, are iron, copper, cobalt, potassium, sodium, and zinc. Other metals—for example, mercury, lead, cadmium, barium, beryllium, radium, and uranium—are very toxic. Some metals at the atomic and ionic levels are crucial for the oxidation process that metabolizes carbohydrates for all living cells. 

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