Copper metabolism in mottled mouse (Mus musculus) mutants. Studies of blotchy (Moblo) mice and a comparison with brindled (Mobr) mice.

1. Copper concentrations were low in many organs of Moblo/Y mice, but very high in the gut. Absorption of 64Cu was seen to be very low when related to the absorption of cyano[57Co]cobalamin. The results in Moblo/+ mice were intermediate. 2. Copper therapy temporarily ameliorated many effects of the mutation in Moblo/Y mice, but did not improve the rate of weight gain as has been achieved previously in Mobr/Y mice. Lower capacity for a 'depot dose' effect at the site of injection may explain the difference. 3. The distribution of 64Cu after administration into the bloodstream of Moblo/Y mice altered from an initially normal state to one that resembled the abnormal distribution of pre-existing copper by 48 h. This indicated that the later mechanisms of copper distribution were at fault. Moblo/+ mice were equally affected. 4. The alteration of copper homoeostasis in blotchy mice was similar to that observed in brindled mice previously and in the present studies, although generally less severe. This is consistent with allelism of the two mutations.     

Copper metabolism in mottled mouse mutants: distribution of 64Cu in brindled (Mobr) mice.

1. Duodenal injection of 64Cu in treated adult mutant mice (Mobr/y) revealed severe malabsorption of copper. In suckling mutants, malabsorption was less severe, owing to delayed absorption between 2 and 5 h after injection. Pinocytosis at the distal small intestine seems the likely explanation for this difference, and this is supported by results of ileal injection of radioisotope in the suckling mice. 2. The distribution of 64 Cu in various organs was measured in suckling normal, mutant and heterozygote mice and in adult normal and mutant mice during 48 h after intracardiac injection. Excessive accumulation of radioisotope was observed in most extrahepatic organs of mutant and heterozygote mice and was most pronounced in kidney. This could not be explained by initial copper deficiency. The livers of suckling mutant and heterozygote mice lost radioisotope rapidly after normal initial uptake. This pattern was not seen in adult mutants.     

Secondary ion mass spectrometry analysis of the copper distribution in Drosophila melanogaster chronically intoxicated with Bordeaux mixture

The fungicides used intensively in agriculture may affect non-target organisms. The concentrations of copper sulfate-based fungicide, Bordeaux mixture, normally used in agriculture, can significantly reduce both the life span and breeding rate of Drosophila melanogaster. The present study examines the distribution of copper in organ sections of fruit flies intoxicated with Bordeaux mixture, by secondary ion mass spectrometry. The organs of most control flies contained no copper. In contrast, copper accumulated in the cytoplasm of all the mesenteron and Malpighian tubule epithelial cells of the treated flies. There were also copper deposits in the fat body and the epithelia of the seminal receptacle and accessory glands of some flies, but there was little or no copper in the ovaries. The mesenteron and Malpighian tubules are generally responsible for detoxification by accumulation of ingested metal salts in insects. The high concentration of Bordeaux mixture used saturated these organs and resulted in excess copper being deposited in other sites, such as the fat body and the reproductive system.     

The tonoplast copper transporter COPT5 acts as an exporter and is required for interorgan allocation of copper in Arabidopsis thaliana

Copper is an essential micronutrient for all organisms because it serves as a cofactor of several proteins involved in electron transfer. Elevated copper concentrations can cause toxic effects and organisms have established suitable mechanisms to regulate the uptake and internal distribution of copper to balance the content at an optimal concentration. In recent studies, a family of copper transporters (COPT) with high homology to other eukaryotic copper transporters (Ctr) has been identified in Arabidopsis thaliana. In this study we clarified the physiological function of COPT5. This carrier is located in the tonoplast and functions as a vacuolar copper exporter. Mutants lacking this transporter have altered copper contents in different organs when compared with wild-type plants. We were able to detect copper accumulation in the root and a decreased copper content in siliques and seeds when the COPT5 gene is mutated by T-DNA insertion. Vacuoles purified from copt5 T-DNA-insertion mutants show remarkably increased copper concentrations compared with wild-type organelles. We assume that on the cellular level COPT5 is important for copper export from the vacuole and on the level of the whole plant it is involved in the interorgan reallocation of copper ions from the root to reproductive organs.     

Biological effects of high copper and zinc concentrations and their interaction in rapeseed plants

In experiments with rapeseed (Brassica napus L., cv. Westar) plants, it was confirmed that copper was considerably more toxic than zinc. The toxic effects of 50 and 150 μM CuSO₄ were comparable to those of 1000 and 2500 μM ZnSO₄. The analysis of the effects of these concentrations of copper and zinc on photosynthetic pigment contents and on the rate of lipid peroxidation did not reveal any reasons for different toxicities of these heavy metals (HM). Among biological effects studied, significant differences were found in the organ distribution of these metals in plants grown on both the standard medium and the medium with high concentrations of copper or zinc. Copper retained in the roots in relatively small amounts and was poorly transported over the aboveground part of the plants. It stayed mainly in the lower leaves, and its distribution changed only a little during the recovery of plants following the HM treatment. In contrast, zinc proved to be highly mobile, it was concentrated in the upper leaves and actively transported when the plants were transferred to a medium with the optimal HM concentrations. High copper concentrations slowed strongly zinc uptake by the roots but practically did not change its movement over the plant. In contrast, high zinc concentrations facilitated copper uptake by the roots but reduced its transfer to the aboveground organs. The data presented here allow us to hypothesize that biological peculiarities of organ and cellular distribution of copper and zinc in plants and interaction of these HM play an important role in the toxic effects of high concentrations of these HM and the mechanisms of adaptation to them at industrial environmental pollution used by rapeseed plants.     

Zinc and copper of fetal organs during the second trimester of pregnancy

In fetus with a mean gestational age of 18 weeks (range 15-25, n = 14), zinc and copper concentrations in liver, femur, rib, and skeletal muscle were measured. Zinc and copper concentrations are highest in liver. A trend of decreasing liver zinc concentrations during gestational age is suggested. Zinc concentrations are significantly correlated with copper concentrations in liver and in femur, suggesting steady growth in both organs. Femur zinc values rank ca. 30% of those in liver, femur copper, ca. 2%. Zinc or copper concentrations in rib are of the same levels as in skeletal muscle. Their concentration for zinc ranks ca. 20%, for copper, ca. 5% of the values in liver. All zinc and copper values are lower than reported in third trimester fetal organs. Calculated zinc/copper molar ratios are distinctive for the various organs: in liver, 6 +/- 1, in femur, 73 +/- 8, and in soft tissues, 26 +/- 3. Calculated ratios from published values obtained from the third trimester of pregnancy show that the ratios in liver and skeletal muscle maintain these levels. The zinc/copper molar ratio can serve as an internal reference in zinc and/or copper measurements.     

Chronological changes in tissue copper, zinc and iron in the toxic milk mouse and effects of copper loading

The toxic milk (tx) mouse is a rodent model for Wilson disease, an inherited disorder of copper overload. Here we assessed the effect of copper accumulation in the tx mouse on zinc and iron metabolism. Copper, zinc and iron concentrations were determined in the liver, kidney, spleen and brain of control and copper-loaded animals by atomic absorption spectroscopy. Copper concentration increased dramatically in the liver, and was also significantly higher in the spleen, kidney and brain of control tx mice in the first few months of life compared with normal DL mice. Hepatic zinc was increased with age in the tx mouse, but zinc concentrations in the other organs were normal. Liver and kidney iron concentrations were significantly lower at birth in tx mice, but increased quickly to be comparable with control mice by 2 months of age. Iron concentration in the spleen was significantly higher in tx mice, but was lower in 5 day old tx pups. Copper-loading studies showed that normal DL mice ingesting 300 mg/l copper in their diet for 3 months maintained normal liver, kidney and brain copper, zinc and iron levels. Copper-loading of tx mice did not increase the already high liver copper concentrations, but spleen and brain copper concentrations were increased. Despite a significant elevation of copper in the brain of the copper-loaded tx mice no behavioural changes were observed. The livers of copper-loaded tx mice had a lower zinc concentration than control tx mice, whilst the kidney had double the concentration of iron suggesting that there was increased erythrocyte hemolysis in the copper-loaded mutants.     

Metabolism of zinc and copper in the neonate: Zinc thionein in developing rat brain,heart, lung,spleen, and thymus

In a continuing study of the importance of metallothionein (MT) in the growth and development of neonates, zinc and copper metabolism in rat brain, heart, lung, spleen, and thymus has been analyzed in 5, 10, 15, 20 and 25 day old rats. Total, cytosol, and MT zinc and copper concentrations and organ contents were determined. Zinc, but very little, if any copper was associated with MT in these organs. Concentrations ranged from 0.03 to 3.3 μg Zn in MT/g; organ contents ranged from 0.003 to 2.2 μg Zn in MT/organ. Brain exhibited the highest concentrations and contents of zinc in MT, approaching the levels found in kidneys. Rank order of organ contents of zinc in MT was brain > lung > heart, spleen, thymus, during this neonatal growth period. When organ growth was rapid, a large percentage (20–95%) of the cytosolic zinc present in these organs was associated with MT, as has been previously observed with liver, kidneys, and testes. None of these organs undergoes the dramatic changes in zinc and copper metabolism previously observed in neonatal rat liver and gastrointestinal tract, and in maturing testes. They are more comparable to kidneys in their concentrations of zinc in MT. Like testes, little copper is found in these organs.     

Fractionation of Soluble Copper- and Zinc-Binding Proteins From Cattle Liver

The distribution of copper and zinc among soluble proteins in liver from normal slaughter cattle was examined after gel filtration of the proteins. Gopper- and zinc-binding proteins were mainly separated into three fractions. Varying amounts of zinc were eluted in a fourth fraction of molecular weight less than 2,000. A clear relationship was noted between the amount of copper bound to the low molecular weight fraction (m.w. ~ 10,000) and the total liver zinc concentration. The high molecular weight protein fraction (m.w. > 65,000) dominated in liver with zinc concentrations below 40 µg/g wet weight and total copper concentrations from 16 to 240 µg/g, while in liver with zinc concentrations above 40 µg/g and copper concentrations ranging from 20 to 107 µg/g, the low molecular weight metallothionein-like fraction dominated.     

The effect that nickel,copper, and zinc salts have on seed germination and initial ontogenesis of water parsnip (<Emphasis Type="Italic">Sium latifolium</Emphasis> L.) and wood club-rush (<Emphasis Type="Italic">Scirpus silvaticus</Emphasis> L.)

The effect that nickel, copper, and zinc sulfates have on seed germination and the initial stages of the ontogenesis of water parsnip and wood club-rush has been investigated. Nickel and copper in the concentration range of 250–500 mg/l and zinc at a concentration of 500 mg/l were the most toxic for water parsnip seeds, while, for the wood club-rush seeds, maximum toxicity was observed at Ni and Cu concentrations ranging from 50 to 500 mg/l and at Zn concentrations of 250–500 mg/l. The development of water parsnip seedlings was normal at Ni concentrations of 1–25 mg/l, Cu concentrations of 1–10 mg/l, and Zn concentrations up to 50 mg/l; the development of wood club-rush seedlings was normal at a Ni concentration of 1 mg/l, and Cu and Zn concentrations of 1–25 mg/l. A further increase in the concentration caused photosynthesis suppression, slower growth of the vegetation organs, and their subsequent necrosis. Water parsnip is more resistant to the toxicants.     

Tissue-and metal-specific effects of thiolacrylic acids in rats

Kidney copper increased 12- to 18-fold above the normal level in rats administered alpha-mercapto-beta-(2-furyl)acrylic acid (MFA). Kidney zinc increased twofold; plasma zinc increased more than 10-fold and liver zinc increased 30–50%. No other changes in copper, iron, and zinc concentrations were found in these tissues or in bone, brain, heart, lung, skeletal muscle, spleen, or testis. Related compounds produced similar effects, although MFA and its disulfide were the most potent of the compounds tested. These increases in tissue copper and zinc were largely complete after 2–5 d of daily administration of compound. Increased plasma zinc returned toward normal with a half-life of 1.0 d for the process, after dosing was ended; albumin was identified as the species binding the excess zinc in plasma. Kidney copper and zinc, which had increased in the ratio of 3 Cu/Zn, returned to normal levels after dosing was stopped with half-lives of 2.1–2.5 d. Consistent with the observations of highly tissuespecific effects of MFA, copper and zinc balances over 8 weeks of trials were found to be not greatly affected by administration of the compound. Thus, it was not established whether excess metal in affected organs derived from enhanced retention of dietary metal or redistribution from other tissues. Kidney copper and zinc and serum zinc increased even in zinc-deficient rats administered MFA.     

Copper Supply in Relation to Content and Redistribution of Copper Among Organs of the Wheat Plant

The relationship of copper supply to the content and movementof copper among organs of wheat plants was examined at sevenstages in their growth from seedlings to maturity on a copperdeficient sand. In the absence of copper (Cu₀), plants becameseverely copper deficient and produced no grain; developmentof tillers, leaves, stems, and inflorescences was delayed andgrowth of roots strongly depressed; leaf senescence was retardedand tiller growth was prolonged. Application of a marginal supplyof copper (Cu₁) overcame all symptoms and promoted growth andgrain production. Increasing copper supply eightfold (Cu₂) didnot change vegetative or grain production. Copper concentrations in stems, individual leaves, and wholetops were highest and responded most strongly to copper supplywhen they were young. As they aged, Cu₁ and Cu₂ leaves lostcopper rapidly; the first Cu₀ leaves retained their copper andremained healthy for more than 7 weeks even though younger leavesdeveloped severe copper deficiency. In all treatments, lossof copper from the oldest leaf paralleled senescence and theloss of nitrogen. It is suggested that copper does not move out of plant leavesuntil they lose organic nitrogen compounds. As a result, copperbehaves in non-senescent leaves as if it is not mobile in plantphloem. But under conditions favouring senescence, copper ishighly mobile: in the present experiment, 67 per cent of thecopper present in vegetative organs of the Cu₂ primary shootat flowering moved from them during grain development and thiscould account for all of the copper found in the grain at maturity. The retention of copper by leaves before senescence, its rapidloss during senescence, and the effect of copper deficiencyin delaying senescence resulted in the oldest leaf of severelydeficient Cu₀ plants in the present experiment having a highercopper concentration than that of copper adequate Cu₁ and Cu₂plants. This behaviour could account for the many reports ofanomalous C-shaped ‘Piper-Steenbjerg’ curves inthe relationship of yield to copper concentrations in planttops. The coupling of copper movement from leaves to nitrogenmovement can also account for the unusually high values reportedfor critical concentrations of copper in tops of plants givenhigh levels of nitrogen fertilizers. Old organs should not be included in samples for diagnosis ofcopper deficiency. Only young organs should be used. In thepresent experiment, the copper concentration of young leavesgave a good indication of the copper status of wheat: a valueof 1 µg g^–1 in young leaves indicated copper deficiency. copper, nitrogen, phloem transport, mineral transport, deficiency diagnosis, wheat, Triticum aestivum L.     

Heavy Metals in the Tissues of Commercially Important Fish of Amurskii Bay,Sea of Japan

The concentrations of iron, copper, zinc, manganese, cadmium, and mercury in tissues and organs of Pacific herring, Far Eastern navaga, and spotted flounder from Amurskii Bay, Sea of Japan, were determined using an atom-absorption method. The distribution of these elements has been studied in organisms of the fish. The greatest concentration of iron, copper, cadmium, and mercury is found in the liver of the fish, manganese is mostly accumulated in the bone tissue, and zinc is found in the skin. Some specific features of metal accumulation in the fish of Amurskii Bay have been revealed. For example, the concentration of iron in the liver of herring and flounder significantly increased the mean concentration known from other areas. A sanitary–hygienic evaluation is provided for the recent levels of metal concentrations in these three species of commercially important fish.     

Effect of dietary copper deficiency on the distribution of dopamine and norepinephrine in mice and rats

Dietary copper deficiency was produced in Swiss albino mice and Sprague Dawley rats to determine the organ specificity of alterations in norepinephrine (NE) and dopamine (DA) concentrations and the relationship with organ copper levels. A 5-week dietary treatment was used, which started 1 week after birth for mice, initially via dams, and 3 weeks after birth for rats. Mice offspring (6 weeks of age) and rats (8 weeks of age) maintained on a copper-deficient (-Cu) treatment were compared with copper-adequate (+Cu) controls. Compared with +Cu animals, -Cu mice and rats were anemic and had low (<1% of +Cu) ceruloplasmin activities but normal body weights. The -Cu mice had organ copper concentrations ranging between 30% and 65% of +Cu values for eight organs studied, with the thymus being the least depleted. For -Cu rats, the range was 15% to 65%. Significant reductions in NE concentration were observed in the heart, pancreas, and spleen of -Cu mice. Elevated DA levels were observed in all organs except the brain. For -Cu rats, the NE level was lower in the heart and the DA level was higher in both the heart and spleen compared with +Cu rats. Dopamine elevation in the heart and spleen for both -Cu mice and rats was four- and fivefold higher, respectively. Adrenal catecholamine levels were only slightly changed by copper deficiency in mice or rats. Urinary levels of both NE and DA were higher in -Cu rats and mice. Plasma and heart tyrosine levels were not altered in -Cu mice. Elevated DA in -Cu rodents may be due to limiting dopamine-beta-monooxygenase. Higher urinary NE and lower organ NE may be due to a combination of decreased synthesis and enhanced turnover. The magnitude of decreased organ copper was not predictive of altered catecholamine pool size.     

A comparison of cadmium-induced metallothionein gene expression and Me2+ distribution in the tissues of cadmiumsensitive (rainbow trout; Salmo gairdneri) and tolerant (stone loach; Noemacheilus barbatulus) species of freshwater fish

1. The accumulation of cadmium in the liver, kidney and gills of rainbow trout and stone loach was measured during exposure of the fish to the metal at 3 smg/l in their aquarium water. The pattern of accumulation of the toxic metal in the individual organs was different between the two species.2. The tissue concentrations of metallothionein-specific mRNA and metallothionein protein were also determined in these organs from the same fish. In rainbow trout, the induction of metallothionein gene expression resulted in a gradual increase in metallothionein concentration in gill over the course of the experiment whereas increases in metallothionein in the liver and kidney were detected only at the later time points of analysis (beyond 19 weeks). By contrast, in the same tissues from stone loach, relatively minor changes were quantified in specific mRNA and metallothionein concentrations.3. Throughout the experimental period, tissue concentrations of zinc and copper were determined in the liver, kidney and gills of the rainbow trout and stone loach. Subtle decreases were observed in the zinc concentration of gills in rainbow trout and substantial increases were observed in the hepatic copper concentrations in both species at the later time points of analysis.4. The ability of cadmium to induce metallothionein gene expression and its subsequent ability to compete for the sequestration sites on the newly-synthesized protein is discussed with regard to the relative levels of cadmium, zinc and copper in the organs studied and differing regimes of cadmium administration.     

Influence of sex,strain, and species on trace metal status of insulin-deficient diabetic rodents

Previous studies have demonstrated marked alterations in trace metal metabolism in male Sprague-Dawley rats following chemical induction of the diabetic state. To determine whether such changes represented a general response to the insulin-deficient condition the levels of zinc, copper, and maganese in liver, kidney, and intestine of normal and streptozotocin (STZ)-diabetic male rats of the Sprague-Dawley, Wistar, and Long-Evans strains, female Sprague-Dawley rats, and male mice were measured. Significantly increased concentrations of zinc, copper, and maganese in liver, and zinc and copper in kidney were found in STZ-diabetic rats, regardless of sex and strain. In contrast, the zinc and copper contents in liver and kidney of control and STZ-diabetic mice were similar, but hepatic manganese levels were significantly elevated in both organs of the diabetic mouse. The concentrations of all three metals were similar in the intestine of control and diabetic rodents. Higher amounts of zinc and copper were bound to metallothionein in the liver and kidney of the diabetic rats. Nicotinamide injection prior to STZ administration protected rats against the development of diabetes and alterations in trace metal status. These data indicate that specific alterations in the metabolism of zinc, copper and manganese during episodes of pancreatic hormonal imbalance represent a general phenomenon in the rat. A possible explanation for the differential response of the STZ-diabetic mouse is discussed.     

Copper metabolism in analbuminaemic rats fed a high-copper diet

Copper metabolism in male Nagase analbuminaemic (NA) rats was compared with that in male Sprague Dawley (SD) rats fed purified diets containing either 5 or 100 mg Cu/kg diet. Dietary copper loading increased hepatic and kidney copper concentrations in both strains to the same extent, but baseline values were higher in the NA rats. There was no strain difference in true and apparent copper absorption nor in faecal endogenous and urinary copper excretion. NA rats had higher levels of radioactivity in kidneys at 2 hr after intraperitoneal administration of ⁶⁴Cu. As based on the distribution of added ⁶⁴Cu, about 70% of plasma copper appeared to be in the non-protein compartment in the NA rats, whereas in SD rats, it was only about 1%. It is concluded that the NA rats are able to maintain a relatively normal metabolism of copper, even after dietary copper challenge. In the NA rats, zinc concentrations in kidneys, liver and urinary zinc excretion were elevated when compared with SD rats. The high-copper diet did not affect tissue zinc concentrations and apparent zinc absorption in both strains of rats.     

The Copper Chaperone CCS Is Abundant in Neurons and Astrocytes in Human and Rodent Brain

Abstract : Copper trafficking in mammalian cells is highly regulated. CCS is a copper chaperone that donates copper to the antioxidant enzyme copper/zinc superoxide dismutase 1 (SOD 1). Mutations of SOD1 are responsible for ~20% of familial amyotrophic lateral sclerosis (FALS). Monospecific antibodies were generated to evaluate the localization and cellular distribution of this copper chaperone in human and mouse brain as well as other organs. CCS is found to be ubiquitously expressed by multiple tissues and is present in particularly high concentrations in kidney and liver. In brain and spinal cord, CCS was found throughout the neuropil, with expression largely confined to neurons and some astrocytes. Like SOD1, CCS immunoreactivity was intense in Purkinje cells, deep cerebellar neurons, and pyramidal cortical neurons, whereas in spinal cord, CCS was highly expressed in motor neurons. In cortical neurons, CCS was present in the soma and proximal dendrites, as well as some axons. Although the distribution of CCS paralleled that of SOD1, there was a 12-30-fold molar excess of SOD1 over CCS. That both SOD1 and CCS are present, together, in cells that degenerate in ALS also emphasizes the potential role of CCS in mutant SOD1-mediated toxicity.     

Dental amalgam mercury exposure in rats

The aim of this study was to measure the distribution of mercury, in tissues of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were either exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured in the kidney, liver and brain, copper in kidney and brain and zinc in kidney. The results showed significantly higher concentrations of mercury in the kidneys and the brains of rats in both exposed groups compared to control. Even after two months of exposure to mercury brain mercury concentration in rats with amalgam fillings was 8 times higher than in the control and 2 times higher than in rats exposed to amalgam supplemented diet. The highest mercury concentration in the latter group was found in the kidneys and it was 5 times higher than in the control group. We found no significant differences between mercury levels in exposed and control rat's liver. Exposure to mercury from dental amalgams did not alter the concentrations of copper and zinc in the tissues. Histopathological analyses of rats tissues did not show any pathological changes. These results support previously proposed nose-brain transport of mercury released from dental amalgam fillings.     

Manganese, copper, zinc, and iron concentrations and subcellular distribution in two types of skeletal muscle

To clarify trace element distribution in red and white muscle, and to verify two populations of muscle mitochondria, the iron, zinc, copper, and manganese concentrations of whole muscle and their subcellular fractions were determined. The iron, zinc, copper, and manganese concentrations of red muscle were 1.83, 4.31, 2.05, and 1.67 times higher than those of white muscle, respectively. In skeletal muscle subcellular distribution or iron, zinc, and copper were entirely different and that of manganese was relatively similar as compared with those in liver reported previously. The pattern of mineral distribution in all fractions of red muscle was similar to that of white muscle, but their concentrations in some fractions were different between red and white muscle, e.g., iron, zinc, and manganese in supernatant fraction and copper in nuclear and microsomal fractions. The difference between subsarcolemmal and interfibrillar mitochondria were ascertained by the distribution of trace elements.