High Copper Status Research Articles

Comparison of X-ray absorption spectra from copper-loaded bovine and ovine livers

BackgroundCopper toxicity and hepatic copper accumulation pose a serious risk to ruminant health and production. Differences in the copper-handling mechanisms of cattle and sheep have been noted, not only in comparison to each other, but also in comparison to ‘copper-tolerant’ monogastric species. Ruminants appear less able to cope with rising liver copper concentration than monogastric counterparts, with sheep in general less able to cope with elevated copper intake than cattle. MethodsX-ray absorption spectroscopy (XAS) was used to investigate the differences between the livers of these species at high copper status. ResultsThe X-ray absorption fine structure (XAFS) and X-ray absorption near edge structure (XANES) spectra indicated that the hepatic copper compound is most likely to be bound to metallothionein; consistent with monogastric species. ConclusionAlthough, most likely stored as copper-metallothionein, there may be a role for glutathione as a short-term, intermediate copper buffer which may have more relevance to sheep than cattle. The potential that thiomolybdate bound copper can be stored in the liver could not be ruled out.

Levels of Selenium, Zinc, Copper, and Antioxidant Enzyme Activity in Patients with Leukemia

Essential elements, mainly selenium and zinc, were involved in protection against oxidative stress in cells. Oxidation could lead to the formation of free radicals that have been implicated in the pathogenesis of many diseases, including leukemia. Leukemia is a neoplastic disease that is susceptible to antioxidant enzyme and essential elements alterations. This study was undertaken to examine the levels of essential elements, antioxidant enzymes activities, and their relationships with different types of leukemia. Serum selenium, zinc, and copper concentrations, red blood cell glutathione peroxidase (GPx) activities, plasma Cu-Zn superoxide dismutase (Cu-Zn SOD) activities and lipid peroxidation (LPO) levels were determined in 49 patients with different types of leukemia before initial treatment. Serum selenium and zinc concentrations were lower in leukemia patients than those of controls (p<0.01). Serum copper concentration was higher in leukemia patients than that of controls (p<0.01). The activities GPx and Cu-Zn SOD were significantly increased in leukemia patients, especially with acute leukemia (AL), acute lymphoid leukemia (ALL), and acute nonlymphoid leukemia (ANLL) (p<0.05), whereas no difference was found between those of chronic myelogenous leukemia and the controls. The levels of LPO were normal as controls. Serum selenium concentration was not correlated with GPx, and serum levels of zinc and copper were not related to Cu-Zn SOD. Serum zinc levels had a negative correlation with the absolute peripheral blast cells, whereas serum copper had a positive correlation with the absolute peripheral blast cells. Increased GPx and Cu-Zn SOD activities and normal levels of LPO, which were a protective responses, were an indicator of mild oxidative stress; it might indicate that the essentials elements alterations in leukemia patients were mostly dependent on tumor activity. Changes of their levels demonstrated that there are low selenium, zinc, and high copper status in leukemia patients. The decrease of plasma zinc and increase of the Cu/Zn ratio could be the index that showed an unfavorable prognosis of acute leukemia.

Influence of liver copper status of mare and newborn foal on the development of osteochondrotic lesions.

To elucidate the highly contentious role of copper in the pathogenesis of osteochondrosis. There would be no relationship between liver copper concentration of mares and foals and incidence of radiographically detectable osteochondrotic lesions in foals and yearlings was tested. Liver copper concentration was assessed in biopsies taken within 4 days after birth from both mares and foals and from the same foals at age 5 months. Biopsies were taken in the standing, sedated animal under ultrasonographic guidance. Radiographs were taken of both hocks (lateromedial, dorsoplantar and dorsomedial-plantarolateral oblique views) and stifles (lateromedial and caudolateral-craniomedial oblique views) at ages 5 and 11 months and scored for the presence and severity of osteochondrotic lesions. Copper concentrations in newborn foals were high with a large variation (351 +/- 201 mg/kg DM). They declined until reaching values comparable to those in mature animals at 5 months (20 +/- 8 mg/kg DM; mares: 19 +/- 20 mg/kg DM). Radiographic osteochondrotic lesions decreased in number and severity from 5 to 11 months. This pattern was more predominant in the stifle than in the hock, as has been described previously. There was no relationship between foal or mare liver copper concentration and osteochondrosis status at either 5 or 11 months. However, osteochondrotic lesions in foals with low-level copper status at birth decreased significantly less in number and severity than those in foals with high-level copper status at birth. It is concluded that copper is not likely to be an important factor in the aetiopathogenesis of osteochondrosis, but this study indicates that there may be a significant effect of high copper status on the natural process of repair of early lesions.

SUPEROXIDE DISMUTASE ACTIVITY AND REDUCED GLUTATHIONE LEVELS IN Cu-OVERLOAD LIVER FROM SHEEP

To explain the cytotoxicity of excessive copper accumulation in the liver of sheep, we measured Cu-Zn superoxide dismutase (SOD) activity, reduced glutathione (GSH) levels and lipid peroxidation in homogenates and subcellular fractions of hepatocytes. Sheep were dosed orally with a 2 per cent solution of CuSO4 on 5 days of the week at the rate of 10 ml per kg body weight, to induce the Cu toxicity. Serum copper levels and acid phosphatase (AP) activity were determined at frequent intervals. At time of the first increase of serum AP activity, three treated sheep (group 2A) were euthanased, and at the first day of hemolysis the others treated sheep (group 2B) also were euthanased. We found high liver Cu content and evidence of lipid peroxidation. In whole homogenate, mitochondrial and microsomal fractions, the thiobarbituric acid reacting substances were increased. This was correlated with an increase in the SOD activity and with decrease of the GSH levels. It could be argued that high copper status might have increased the SOD activity and induced lowest levels of GSH. Additionally, lipid peroxidation was induced by Cu-overload.Copyright © 1996 Elsevier Science Inc.

Antioxidant capacity of erythrocytes from sheep chronically poisoned by copper

Some indicative factors of antioxidant capacity in erythrocytes from chronic copper poisoning in sheep, were evaluated. Levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, reduced glutathione (GSH) and response to oxidative shock have been determined in animals with high and normal copper status. High copper status might have limited the SOD activity and induced lowest levels of GSH. This was associated with an increase of TBA reactivity in lipid peroxidation induced by hydrogen peroxide. In addition, GSH-Px activity did not differ significantly from that of control sheep. Our results demonstrate a direct correlation between the level of serum copper and a decrease in the evaluated antioxidant mechanisms. It is reasonable to postulate that non-specifically bound copper could be involved in cellular injury.

Serum Copper and the Risk of Acute Myocardial Infarction: A Prospective Population Study in Men in Eastern Finland

The authors investigated the association of serum copper concentration with the risk of acute myocardial infarction in 1,666 randomly selected men aged 42, 48, 54, or 60 years who had no symptomatic ischemic heart disease at entry. Baseline examinations in the Kuopio Ischaemic Heart Disease Risk Factor Study in Eastern Finland were done during 1984 to 1988. In Cox multivariate survival models adjusting for age, examination year, ischemic electrocardiogram in exercise, maximal oxygen uptake, diabetes, family history of ischemic heart disease, cigarette-years, mean systolic blood pressure, serum high density lipoprotein (HDL) cholesterol subfraction HDL2 and low density lipoprotein (LDL) cholesterol concentrations and blood leukocyte count, serum copper concentration in the two highest tertiles (1.02-1.16 mg/liter and 1.17 mg/liter or more) associated with 3.5-fold (95% confidence interval (Cl) 1.3-9.4, p less than 0.05) and 4.0-fold (95 percent Cl 1.5-10.8, p less than 0.01) risk of acute myocardial infarction. These data indicate that high copper status, reflected by elevated serum copper concentration, is an independent risk factor for ischemic heart disease.

Heinz body anaemia in lambs with deficiencies of copper or selenium.

1. The progression of Heinz body anaemia was studied in groups of lambs of low- and high-copper status, produced through breeding or Cu supplementation, when they were transferred from improved pasture to rape (Brassica napus L.) in autumn. Some lambs had previously received selenium by injection. The Cu and Se supplements markedly increased superoxide dismutase (EC 1.15.1.1; SOD) and glutathione peroxidase (EC 1.11.1.9; GSHPx) activities respectively in the erythrocytes, and both supplements had elicited growth responses at pasture. 2. At the time of transfer to rape, lambs not treated with Cu had lower whole-blood haemoglobin (Hb) concentrations and a higher percentage of erythrocytes containing Heinz bodies (6.6 v. 3.7%, P less than 0.01) than Cu-treated lambs: the corresponding effects of Se treatment were similar in direction but lower in magnitude (P less than 0.05). 3. After grazing rape for 2 weeks the mean Hb concentration had fallen by 30 g/l while Heinz body count had increased from 5 to 25%. However, counts were negatively correlated with the initial values and were unaffected by the Cu and Se treatments which maintained high plasma Cu concentrations and SOD and GSHPx activities. 4. The results provide the first evidence that Cu deficiency can induce Heinz body formation and the anaemia in grazing Cu-deficient lambs may be partly haemolytic in origin. The concomitant Se deficiency added marginally to the problem but neither the separate nor combined deficiencies increased the susceptibility of lambs to brassica anaemia.

Studies on lambs from lines genetically selected for low and high copper status 1. Differences in mortality

ABSTRACTMortality and its causes were studied during two consecutive years in a total of 934 lambs. The lambs were from two lines of sheep genetically selected for low (L) and high (H) concentrations of copper (Cu) in plasma within an interbred Scottish Blackface × Welsh Mountain population and from unselected Scottish Blackface (B) and Welsh Mountain (W) breeds. The lambs grazed improved hill pastures. Half of the lambs in each line or breed were given an oral Cu supplement by 7·5 weeks of age.Mortality from birth to 24 weeks in H was less than half that in L; mean proportional mortalities were L 0·28, H 0·12, B 0·37 and W 0·07, with a similar distribution in each year. Swayback accounted proportionately for 0·26 deaths in year 1, but proportionately for only 0·02 in year 2. The majority of other losses involved a variety of microbial infections.Genetic type (W &lt; H &lt; L &lt; B) was a major determinant of, and Cu supplementation a protection against, swayback and non-swayback losses. For non-swayback losses L lambs were about twice (P&lt; 0·01) and B lambs about four times (P&lt; 0·001) more vulnerable than H and W lambs respectively. Unsupplemented lambs were more than twice as vulnerable to non-swayback causes of death in the 1st year (P&lt; 0·05) and four times as vulnerable in the 2nd year (P&lt; 0·01) as were Cu-supplemented lambs. There were no cases of swayback in supplemented lambs even though Cu treatment was in some lambs as late as 7·5 weeks after birth.Such marked differences in mortality rate, particularly between the selected lines, had not been apparent in the 5 years preceding pasture improvement, suggesting a genotype × environment interaction affecting survival.The results provide the first definitive evidence that decreased resistance to infection is a clinical consequence of ovine Cu deficiency in the field, amenable to control by Cu treatment and genetic selection.

Studies on lambs from lines genetically selected for low and high copper status 2. Incidence of hypocuprosis on improved hill pasture

ABSTRACTGrowth rate and the concentrations of various biochemical constituents were measured in 2 years in lambs from two lines, selected on low (L) and high (H) copper (Cu) concentrations in plasma, and from two unselected pure breeds, Scottish Blackface (B) and Welsh Mountain (W). The lambs grazed improved hill pastures and half were given Cu supplements.H lambs were always heavier and were fattened for slaughter earlier than were L lambs, differences that were not completely eliminated when supplementary Cu was given. In both years, the improvements in growth rate due to supplementary Cu varied with genetic type (average L 20·5 (s.e. 2·5); H 5·7 (s.e. 2·6); B 25·1 (s.e. 3·7); W 8·1 (s.e. 3·3) g/day). Growth rates of supplemented lambs were L 100 (s.e. 2), H 104 (s.e. 2), B 134 (s.e. 5), W 103 (s.e. 3) g/day.At 6 weeks of age, unsupplemented lambs trom all genetic types were hypocupraemic and, at all ages, unsupplemented L and B lambs had lower concentrations of Cu in plasma and superoxide dismutase (SOD) activity than had unsupplemented H and W lambs. Supplemented lambs always had greater concentrations of Cu in plasma and SOD activities than had their unsupplemented counterparts. Supplementation increased the haemoglobin concentration for B (in year 2) and L lambs but not for H and W lambs. Cholesterol concentrations in plasma were unaffected by selection but were slightly higher in unsupplemented lambs. The concentration of total protein and the activity of aspartate transaminase were unaffected by genotype or Cu supplementation. In the liver of lambs at slaughter, the concentration of Cu was lower for unsupplemented lambs and inversely related to the concentration of iron.It was concluded that (i) genotype was an important determinant of hypocuprosis; (ii) the degree of hypocuprosis could not be predicted from herbage analyses alone, but instead may be predicted from biochemical assessment of the lamb; and (iii) the dose of Cu supplement used was inadequate for L and B lambs and recommended levels could be increased, within limits, without risk of toxicity.

Levels of enzyme activities in blood serum as indicators of a high copper status in sheep flocks.

SummaryThe relationship between the hepatic Cu‐level and certain biochemical constituents in the blood of lambs was studied. The activities of the enzymes glutamic oxaloacetic transaminase (E.C. 2.6.1.1.), sorbitol dehydrogenase (E.C. 1.1.1.14.) and to a lesser extent γ‐glutamyl transferase (E.C. 2.3.2.2.) can be considered as indicators of a high copper status of a flock. When the copper status is very high (&lt; 1500 μg Cu per g DM in the liver) the activity of lactate dehydrogenase (E.C. 1.1.1.27.) is strongly enhanced. For individual animals, the estimation of these enzymes is of little diagnostic value in predicting the Cu‐status. The influence of hepatic Cu‐levels lower than 600 μg per g DM on any of the parameters determined in the blood was slight.ZusammenfassungEnzymaktivitäten im Blutserum als Indikatoren für einen hohen Kupferstatus in SchafherdenDie Beziehungen zwischen dem Kupfergehalt der Leber und gewissen biochemischen Parametern im Blut der Lämmer wurde untersucht. Die Aktivitäten folgender Enzyme können als Indikatoren für einen hohen Kupferstatus einer Herde betrachtet werden: Glutamat‐Oxalacetat‐Transaminase (E.C. 2.6.1.1.), Sorbit‐Dehydrogenase (E.C. 1.1.1.14.) und in einem geringeren Ausmaß γ‐Glutamyl‐Transferase (E.C. 2.3.2.2.). Bei sehr hohem Kupferstatus (&lt; 1500 μg Cu pro g Trockenmasse in der Leber) ist auch die Aktivität der Laktat‐Dehydrogenase (E.C. 1.1.1.27.) stark erhöht. Bei individuellen Tieren dagegen ist die Bestimmung der Enzymaktivitäten von geringer diagnostischer Aussagekraft bezüglich des Kupferstatus. Bei Kupfergehalten in der Leber von weniger als 600 μg pro g TM war der Einfluß auf die untersuchten Parameter nur gering.RésuméActivités enzymatiques dans le sérum sanguin comme indicateurs d'un statut élevé du cuivre dans des troupeaux de moutonsOn a examiné le rapport entre le taux du cuivre dans le foie et certains paramètres biochimiques dans le sang d'agneaux. Les activités enzymatiques suivantes peuvent être considérées comme indicateurs pour un statut élevé en cuivre d'un troupeau: glutamate‐oxalacétate‐transaminase (E.C. 2.6.1.1.). sorbit‐déhydrogénase (E.C. 1.1.1.14.) et dans une moindre mesure γ‐glutamyl‐transférase (E.C. 2.3.2.2.). L'activité de lactate‐déhydro‐génase (E.C. 1.1.1.27.) est fortement augmentée avec un statut très élevé du cuivre (&gt; 1500 μg Cu pro g substance sèche dans le foie). La détermination des activités enzymatiques est d'une moindre valeur pour le diagnostic concernant le statut du cuivre chez des animaux pris individuellement. L'influence sur les paramètres recherchés fut faible avec des taux de cuivre dans le foie inférieurs à 600 μg pro g substance sèche.ResumenLos niveles de actividades enzimáticas en el suero sanguíneo coma indicadores del estado elevado de cobre en rebaños de ovinosSe examinaron las relaciones entre el contenido de cobre en el hígado y ciertos parámetras bioquímicos en la sangre de los corderas. Las actividades de las enzimas siguientes se pueden considerar como indicadoras de un estado elevado de cobre: glutamato‐oxalacetato‐transaminasa (E.C. 2.6.1.1.), sorbita‐dehidrogenasa (E.C. 1.1.1.14.) y, en menor magnitud, γ‐glutamil‐transferasa (E.C. 2.3.2.2.). Con estado muy elevado de cobre (&gt; 1500 μg Cu por g MD en el hígado) también se encuentra muy incrementada la actividad de la lactato‐dehidrogenasa (E.C. 1.1.1.27.). Sin embargo, en animales individuals la valoración de las actividades enzimáticas tiene un valor diagnóstico de predicción muy escaso en cuanto al estado de cobre. En los niveles de cobre en hígados inferiores a 600 μg por g MD era solo muy limitado el influjo sobre los parámetras determinados en sangre.

CHRONIC COPPER TOXICITY IN LAMBS: A SURVEY OF BLOOD CONSTITUENT RESPONSES

Blood chemistry of lambs was studied during the period of liver copper accumulation in chronic copper toxicity. In trial 1, dietary copper was 10.9, 17.8 and 25.2 mg/kg. During a 10-wk feeding trial no mortalities due to copper toxicity and no differences in growth rate were found (P &gt; 0.05). At slaughter, liver copper levels were 239, 454 and 721 μg/g of dry matter, respectively (P &lt; 0.05). There was no response to added dietary copper for hematocrit, ferroxidase, aspartate aminotransferase, allantoin, plasma protein, catalase, molybdenum or plasma copper (P &gt; 0.05). In trial 2, dietary copper was 9.1 and 37.3 mg/kg. Lambs were individually fed for an 11-wk feeding trial. No mortalities or difference in growth occurred (P &gt; 0.05). At slaughter, liver copper levels were 372 and 1109 μg/g of dry matter, respectively (P &lt; 0.05). Plasma aspartate aminotransferase was elevated in response to added dietary copper (P &lt; 0.05). No effect due to added dietary copper was found with superoxide dismutase, alkaline phosphatase, ferroxidase, lactate dehydrogenase, plasma protein, hemoglobin, plasma copper, calcium, inorganic phosphate, cholesterol, triglyceride, uric acid, urea nitrogen or hematocrit (P &gt; 0.05). Only plasma aspartate aminotransferase and liver copper concentration could be considered useful indicators of high copper status.