Metabolism of copper

A blue, copper-containing glycoprotein present in mammalian blood plasma and containing type 1, type 2, and type 3 copper centers. The type 2 and type 3 copper centers are close together, forming a trinuclear copper cluster. Ceruloplasmin has an important role in the transport and storage of copper ions. Thus, it participates in the metabolism of copper-containing enzymes. 

A second example of cluster formation involves the antagonism between molybdenum and copper. The presence of high concentrations of molybdenum in pasture soils is known to lead to symptoms of copper deficiency in animals. This has been attributed to the formation of thiomolyb-dates in the rumen of grazing animals, which then interfere with the metabolism of copper through the formation of cluster compounds of molybdenum and copper. It has been shown that thiomolyb-date, MoS42, readily forms such clusters on reaction with phosphines and copper(II) salts under appropriate conditions. Structures are shown in Figure 38.992,993 Reaction between thiomolybdate and copper compounds in aqueous solution have also been reported.994... 

Metallothioneins play an important role in the metabolism of copper, both in absorption and handling by the liver. Dietary supplementation with copper leads to a large increase in liver copper-metallothionein. The biological life of metallothionein can vary considerably. The half-life of Cu-metallothionein in zinc-deficient rats (12.3 h) was lower than that in zinc-sufficient rats (16.9 h).1166 Usually zinc is found in Cu-metallothionein, so zinc may stabilize the copper metallothionein.1167... 

Bremner, X Involvement of metallothioneins in hepatic metabolism of copper. J. Nutr. 1987 117 19-24... 

Cousins, R. J, (1985). Absorption, transport, and hepatic metabolism of copper and zinc Special reference to metallothjonein and ceruloplasmin. Physiol. R t 65,238-309. 

Hormonal Control of Copper Metabolism Recent evidence suggests that metabolism of copper as well as zinc is controlled by the pituitary-adrenal axis (97,98,99). For example, administration of large doses of corticosteroids in humans leads to rapid and sustained drop in serum copper and zinc. Pregnant women and women on oral contraceptive agents show a significant increase in serum copper levels (iOO, 101,102),... 

In animals, bismuth interferes with the metabolism of copper and zinc, induces metallothionein, and can... 

Figure 30-26 Metabolism of copper. (Modified from Harris ED. Copper, In O Dell BL, Sunde RA, eds. Handbook of nutritionally essential mineral elements. New Vbr/c /Morce/ DeWcer, 1997 231-73.)...

Disturbance of Copper Metabolism. A profound and characteristic disturbance of the metabolism of copper is the cardinal biochemical feature of Wilson s disease. The earUest evidence of this came from Germany, where in 1913 Rumpel (R20) found increased copper and silver content of the liver in patients with so-called pseudosclerosis. Siemerling and Oloff (S27) as far back as 1922 suggested that the pseudosclerosis of Westphal-Striimpell is actually due to accumulation of copper salts in the nervous system, liver, and eye. These early observations were not followed up for over 20 years, until Glazebrook (G7) in 1945 reported high copper content in the liver and brain of a patient with Wilson s disease, and increased... 

Koropatnick J, Leibbrandt M, Cherian MG (1989) Organ-specific metallothionein induction in mice by x-irradiation. Radiat Res 119 356-365 Lehman-McKeeman LD, Kershaw WC, Klaassen CD (1991) Species differences in metallothionein regulation a comparison of the induction of isometallothioneins in rats and mice. In Klaassen CD, Suzuki KT (eds) Metallothionein in biology and medicine, CRC, Boca Raton, pp 121-132 Lui EMK (1987) Metabolism of copper and zinc in the liver and bone of perinatal guinea pig. Comp Biochem Physiol 86 173-183 Maitani T, Cuppage FE, Klaassen CD (1988) Nephrotoxicity of intravenously injected cadmium-metallothionein critical concentration and tolerance. Fund Appl Toxicol 10 98-108... 

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