Cu-deficient Group Research Articles

Analysis of the value of copper erythrocyte concentration measurement in the diagnosis of copper deficiency in bovines

BackgroundA reliable and practical method for assessing Cu status in live animals is not available. Blood Cu levels may not accurately reflect the true Cu status of the herd, and can over-predict Cu status during stress and inflammation. On the other hand, assessment of liver Cu is the most reliable indicator of Cu stores, but it is an invasive procedure that requires specialized training. The aim of this study was to evaluate the usefulness of Cu levels in red blood cells to determine the Cu status, with special emphasis in their correlation with erythrocyte Cu, Zn superoxide dismutase enzyme activity (ESOD), in bovines with Cu deficiency induced by high molybdenum and sulfur levels in the diet. MethodsThree similar assays were performed, with a total of twenty eight calves. The Cu-deficient group (n = 15) received a basal diet supplemented with 11 mg of Mo/kg DM as sodium molybdate, and S as sodium sulfate. The control group (n = 13) received a basal diet supplemented with 9 mg of Cu/kg DM as copper sulfate.Samples of blood and liver were taken every 28–35 days. Cu levels were measured in liver (expressed as µg/g DM), plasma (expressed as µg/dl), and erythrocytes (expressed as µg/g Hb) by flame atomic absorption spectroscopy. Superoxide dismutase (SOD1) activity was determined in red blood cells and was expressed as IU/mg hemoglobin.InfoStat Statistical Software 2020 was used for the statistical analysis. Cu levels in plasma, red blood cells and liver, and ESOD activity were analyzed by ANOVA. The correlation between erythrocyte Cu levels and the rest of the parameters were analyzed by Pearson Correlation test. Unweighted Least Squares Linear Regression of SOD1 was developed. The autocorrelation between the monthly measurements was also determined by Durbin-Watson test and autocorrelation function. ResultsThe assays lasted 314–341 days, approximately. Levels indicative of Cu deficiency for bovines were detected at 224 days (23 ± 11.6 µg/g DM) for liver Cu concentration; and at 198 days (55 ± 10.4 µg/dl) for plasma Cu concentration, in Cu-deficient animals. Liver and plasma Cu values indicative of Cu deficiency were not observed in the control group.Pearson Correlation test indicated that all indices of Cu status used in this study were significantly correlated. The highest value was obtained between ESOD and red blood Cu (0.74). There was a significant correlation between red blood Cu and plasma Cu (0.65), and with hepatic Cu (0.57). ESOD activity showed a similar significant positive correlation with liver Cu concentrations and with plasma Cu (0.59 and 0.58, respectively). ConclusionThe extremely low levels of liver and plasma Cu, the ESOD activity, erythrocyte Cu levels, and the periocular achromotrichia observed in the Cu-deficient animals showed that the clinic phase of Cu deficiency was reached in this group. The ESOD activity and erythrocyte Cu levels showed a strong association, indicating that the values of erythrocyte Cu may serve as an effective tool in assessing Cu status and diagnose a long-term Cu deficiency in cattle.

Effects of dietary copper deficiency on adipocyte functions in a rat model of high-fructose diet-induced obesity

Background High fructose intake has been reported to impair copper (Cu) status, leading to low Cu availability with exacerbation of Cu-deficiency complications. These Cu–fructose interactions have been well documented in rats. Aims This experimental study was designed to evaluate the effects of dietary Cu deficiency on lipid profile in addition to adipocyte functions in the form of adiponutrin level and antioxidant capacity in a high-fructose diet-induced obesity rat model. Materials and methods The study was conducted on 60 male albino rats that were divided randomly into four equal groups as follows: group I (control group), group II (Cu-deficient group), group III (high fructose group), and group IV (Cu-deficient/high-fructose group). Plasma Cu level was measured by inductively coupled plasma optical emission spectrometry. Plasma ceruloplasmin and adipose tissue superoxide dismutase activities were assayed calorimetrically. Adiponutrin level in adipose tissue was measured by enzyme-linked immunosorbent assay. Results Plasma Cu level, ceruloplasmin activity, and adipose tissue superoxide dismutase activity were significantly decreased in Cu-deficient/high-fructose group when compared with other studied groups. However, adiponutrin level in adipose tissue was significantly increased in Cu-deficient/high-fructose group compared with other studied groups. Conclusion The modulated adiponutrin level, oxidative stress, dyslipidemia, and adipose tissue inflammation were highlighted as the principal culprits mediating Cu-deficiency and high-fructose diet complications such as nonalcoholic steatohepatitis.

Identification of eight copper (Cu) uptake related genes from yellow catfish Pelteobagrus fulvidraco, and their tissue expression and transcriptional responses to dietborne Cu exposure

The present working hypothesis is that absorption of dietary Cu is related to mRNA expressions of genes involved in Cu uptake and transport of the intestine in fish. To this end, the full-length cDNA sequences of eight Cu uptake related genes, including two isoforms of copper transporter genes (ctr1 and ctr2), three copper chaperone genes (atox1, ccs and cox17), two Cu-ATPase genes (atp7a and atp7b) and divalent metal ion transporter 1 (dmt1), were cloned and characterized in yellow catfish P. fulvidraco, respectively. Their mRNA tissue expression and transcriptional responses to dietborne Cu exposure were investigated. Compared to the corresponding members of mammals, all of these members in P. fulvidraco shared the similar conserved domain structures. Their mRNAs were expressed in a wide range of tissues (including liver, muscle, spleen, brain, gill, intestine, heart and kidney), but at variable levels. In anterior intestine, mRNA levels of ctr1, cox17, dmt1 and atp7a declined with increasing dietary Cu levels. The mRNA levels of ctr2 and mt were the highest for excess dietary Cu group and showed no significant differences between other two treatments. Atox1 mRNA levels were the highest for Cu-deficient group and showed no significant differences between other two treatments. The mRNA levels of ccs were the highest for Cu-deficient group, followed by Cu-excess group and the lowest for adequate-Cu group. In contrast, atp7b mRNA levels were the highest for Cu-excess group and the lowest for adequate Cu group. In the mid-intestine, mRNA levels of ctr1, ctr2, atox1, ccs, cox17, dmt1 and atp7a declined with increasing dietary Cu levels. Atp7b mRNA levels were the lowest for adequate Cu group and showed no significant differences between other two treatments. Mt mRNA levels were the lowest for adequate Cu group and highest for Cu-excess group. For the first time, our study cloned and characterized ctr1, ctr2, atox1, ccs, cox17, atp7a, atp7b and dmt1 genes in P. fulvidraco and determined their tissue-specific expression, and transcriptional responses in the anterior and mid-intestine of yellow catfish under dietborne Cu exposure, which shed new light on the Cu uptake system and help to understand the molecular mechanisms of Cu homeostasis in fish.

Cyclooxygenase-2 is Upregulated in Copper-Deficient Rats

Copper deficiency inactivates Cu/Zn-SOD and promotes accumulation of reactive oxygen species. This process likely impairs nitric oxide (NO)-mediated relaxation as well as triggers vascular inflammation. The current study was designed to determine whether COX-2, a proinflammatory protein, expression and activity are upregulated in the oxidative environment associated with inadequate Cu. Weanling male Sprague Dawley rats were fed purified diets which were either Cu-adequate (Cu-A); Cu-marginal (Cu-M), Cu-deficient (Cu-D), or the Cu-D diet combined with the SOD mimetic Tempol (Cu-D/T; 1 mM in drinking water) for 4 weeks. COX-2 protein, PGE(2) (COX-2 metabolite) and isoprostanes (index of oxidative stress) were all higher in the Cu-D group vs Cu-A group, but no significant differences occurred between the Cu-M and Cu-A groups. Tempol protected against an attenuation of NO-mediated vasodilation in the Cu-D rats but did not prevent the elevation of PGE(2) or isoprostanes. Our data suggest a role for copper as a modulator of oxidative stress and inflammation independent of SOD activity or NO-derived oxidants.

Copper Deficiency Does Not Lead to Taurine Deficiency in Rats

Copper deficiency has been reported to cause a decrease in urinary taurine excretion in rats. We determined whether Cu deficiency would decrease taurine status and the hepatic activities of cysteine dioxygenase (CDO) and/or cysteine sulfinic acid decarboxylase (CSAD) in rats. Ten weanling male rats were assigned to either a Cu-adequate (+Cu) or Cu-deficient (−Cu) group. All rats consumed a Cu-deficient purified diet and water ad-libitum for 16 wk. The water for the +Cu group contained 20 mg Cu/L as CuSO4. At wk 16, the groups differed (P < 0.05) in the following variables (means ± SEM, −Cu vs. +Cu): body weight (BW), 375 ± 19 vs. 418 ± 2.9 g; food intake, 16.2 ± 0.7 vs. 18.5 ± 0.4 g/d; hematocrit, 0.294 ± 0.027 vs. 0.436 ± 0.027; hemoglobin, 95.2 ± 9 vs 134 ± 10 g/L; liver Cu, 8.7 ± 2.0 vs. 65.9 ± 2.5 nmol/g; plasma Cu, 0.38 ± 0.09 vs. 13.4 ± 0.61 μmol/L; plasma ceruloplasmin activity, 1.75 ± 1.0 vs. 67.9 ± 8.4 IU; relative heart weight, 0.56 ± 0.04 vs. 0.35 ± 0.02% BW; relative liver weight, 4.06 ± 0.23 vs. 3.37 ± 0.06% BW; and liver CSAD activity, 18.8 ± 1.37 vs. 13.5 ± 1.11 nmol · min−1 · mg protein−1. The groups did not differ at wk 16 in: plasma taurine, 249 ± 14 vs. 298 ± 63 μmol/L; whole blood taurine, 386 ± 32 vs. 390 ± 25 μmol/L; urinary taurine excretion, 82.5 ± 15 vs. 52.0 ± 8.3 μmol/d; liver taurine, 2.6 ± 0.7 vs. 2.8 ± 0.4 μmol/g; liver total glutathione, 6.9 ± 0.48 vs. 6.3 ± 0.40 μmol/g; liver cyst(e)ine, 96 ± 7.1 vs. 99 ± 5.3 nmol/g and liver CDO activity, 2.19 ± 0.33 vs. 2.74 ± 0.21 nmol · min−1 · mg protein−1. These findings support the conclusion that Cu deficiency does not affect body taurine status.

Effect of Copper Deficiency on Blood Lipid Profile and Haematological Parameters in Broilers

The aim of the study was to observe the changes in haematological parameters and blood lipid profile through copper (Cu) deficiency. Eighty broiler chicks were used in the study. The chicks were separated into two equal groups (n = 40), feed treatment according to the groups started on day 7. The animals in the control group were fed with normal feed. Those in the Cu-deficient group were fed with feed that did not contain supplemental Cu. Blood samples were taken from all the animals on days 7, 21 and 49. Fibrinogen and prothrombin time were assayed in plasma; total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol (LDL-cholesterol), triglyceride and ceruloplasmin were assayed in sera; and haematocrit and thrombocyte levels were assayed in the blood samples. Total cholesterol, triglyceride and LDL-cholesterol levels were significantly higher in the Cu-deficient group than in the control group. Serum ceruloplasmin levels were lower in the Cu-deficient group than in the control group. Prothrombin time was higher in the Cu-deficient group than in the control group. Haematocrit levels were lower in the Cu-deficient group than in the control group. It was concluded that Cu deficiency created hypertriglyceridaemia, hypercholesterolaemia, insufficient growth and anaemia in broilers.

Impaired Deformability of Copper-Deficient Neutrophils

We have previously shown that dietary copper deficiency augments neutrophil accumulation in the lung microvasculature. The current study was designed to determine whether a diet deficient in copper promotes neutrophil chemoattraction within the lung vasculature or if it alters the mechanical properties of the neutrophil, thus restricting passage through the microvessels. Sprague-Dawley rats were fed purified diets that were either copper adequate (6.3 microg Cu/g diet) or copper deficient (0.3 microg Cu/g diet) for 4 weeks. To assess neutrophil chemoattraction, bronchoalveolar lavage fluid was assayed for the neutrophil chemokine macrophage inflammatory protein-2 (MIP-2) by enzyme-linked immunosorbent assay. Neutrophil deformability was determined by measuring the pressure required to pass isolated neutrophils through a 5-microm polycarbonate filter. The MIP-2 concentration was not significantly different between the dietary groups (Cu adequate, 435.4 +/- 11.9 pg/ml; Cu deficient, 425.6 +/- 14.8 pg/ml). However, compared with controls, more pressure was needed to push Cu-deficient neutrophils through the filter (Cu adequate, 0.150 +/- 0.032 mm Hg/sec; Cu deficient, 0.284 +/- 0.037 mm Hg/sec). Staining of the filamentous actin (F-actin) with FITC-Phalloidin showed greater F-actin polymerization and shape change in the Cu-deficient group. These results suggest that dietary copper deficiency reduces the deformability of neutrophils by promoting F-actin polymerization. Because most neutrophils must deform during passage from arterioles to venules in the lungs, we propose that copper-deficient neutrophils accumulate in the lung because they are less deformable.

Effects of Se, Cu and Se + vitamin E deficiency on the activities of CuZnSOD, GSH-Px, CAT and LPO levels in chicken erythrocytes.

Antioxidant enzymes and vitamins provide a defence against the damage of cells by reactive oxygen species in living systems. The effect of Cu, Se and vitamin E deficiencies on the antioxidant enzyme activities and lipid peroxide levels of chicken erythrocytes were investigated during 6 weeks of a depletion diet. CuZnSOD activity and the plasma Cu level of the Cu-deficient group which was fed a diet containing 0.2 mg Cu x kg(-1) were reduced to 62 and 71% respectively. GSH-Px activity of the Se-deficient group was decreased by 46% but by 21% in the Cu-deficient group. CAT activity values of Se- and Cu-deficient groups were increased by 28 and 10% respectively. The maximum increase of LPO levels in erythrocyte membranes was observed as 32% for the Se+E-deficient group. The LPO level of the Cu-deficient group which had decreased CuZnSOD and GSH-Px activity, was also observed to be significantly increased when compared with the controls (p < 0.05).

Experimental Copper Deficiency, Chromium Deficiency and Additional Molybdenum Supplementation in Goats – Pathological Findings

Secondary copper (Cu) deficiency, chromium (Cr) deficiency and molybdenosis (Mo) has been suggested to cause the "mysterious" moose disease in the southwest of Sweden. The present experiment was performed on goats to investigate the clinical, chemical, and pathological alterations after 20 months feeding of a semi-synthetic diet deficient in Cu and Cr. Four groups were included in the study: control group (n = 4), Cu-deficient group (group 1, n = 4), Cr-deficient group (group 2, n = 2) and Cu+Cr-deficient group (group 3, n = 3). Group 3 was additionally supplemented with tetrathiomolybdate during the last 2 months of the experiment. Main histopathological findings in groups 1 and 3 were the lesions in the liver, characterised by a severe active fibrosis, bile duct proliferation, haemosiderosis and mild necroses. Additionally, degenerative alterations of the exocrine pancreas were prominent in groups 1 and 3. Lesions in group 3 were more pronounced than in group 1. In group 3, the skin showed an atrophic dermatosis, while in group 2 a crusty dermatitis caused by Candida spp. was observed. This study shows that liver, pancreas and skin are mainly affected by a long term deficiency of copper and the findings are complicated by molybdenum application while chromium deficiency produced no histomorphological effects in our study.

Experimental copper and chromium deficiency and additional molybdenum supplementation in goats. II. Concentrations of trace and minor elements in liver, kidneys and ribs: haematology and clinical chemistry

Since the mid-1980s a previously undescribed disease has affected moose in south-western Sweden. Investigations made to reveal evidence of a viral aetiology have proved unsuccessful. Trace element studies in apparently healthy moose shot during regular hunting suggested a trace element imbalance, with excessive molybdenum uptake causing secondary copper deficiency. The results also indicated a possible chromium deficiency. To verify this hypothesis, an experimental study was performed in male goats fed a semi-synthetic diet for 1.5 years. The animals were kept and treated in four groups: Controls, Cu-deficient group (group 1), Cr-deficient group (group 2), and combined Cu- and Cr-deficient group with additional supplementation of tetrathiomolybdate for 10 weeks at the end of the study (group 3). The present paper presents tissue contents of trace and minor elements, haematology and clinical chemical parameters. Feed consumption and weight development, as well as pathological and histopathological investigations, were also performed in this study, but these results are presented elsewhere. Changes in trace element concentrations were determined by comparing groups 1, 2 and 3 with the control group. Increased concentrations were observed for Al, Ca, Co, Fe, Mo, Pb, Se in the liver; for Al, Cd, Co, Cr, Mo in the kidneys; and for Mn and Mo in the ribs. Considerable accumulation of Mn in ribs seems to be a useful way to determine oxidative stress. Decreases in Mg and P in all organs and blood serum is characteristic of Cu deficiency and molybdenosis. Also the ratio of Ca/Mg was increased as the result of tissue lesions causing an intracellular increase in Ca and decrease in Mg. The trace element changes observed in group 1 were enhanced by the Mo supplementation in group 3, resulting in characteristic patterns, ‘spectra’ of changes. The alterations were not as remarkable in group 2 as in the two other groups. However, Cr deficiency considerably influenced Al, Co, V and to a smaller extent also Mn in ribs. In groups 1 and 2, only a few minor changes were detected in the haematological parameters, probably caused by increased adrenal activity after transportation of the animals. In group 3, severe anaemia was present but also a leukopenia. For the different clinical chemical parameters measured, all three groups showed changes, explained mainly by the altered activity of enzymes induced by trace element deficiencies and imbalance. Impaired carbohydrate and lipid metabolism was seen in groups 1 and 3, with increased concentrations of glucose, lactate and triglycerides in serum. Increased concentrations of total bilirubin were measured in all three groups (bile stasis was also seen post mortem). A considerably increased concentration of serum urea was found in group 3, although there were no indications of renal insufficiency or dehydration. Regarding hormones, a substantial decrease was seen in thyroxine (T 4) in group 3 as a result of the molybdenosis, but a minor decrease was also seen in group 1. Insulin on the other hand showed increased levels in group 3 — and especially in group 2 due to the Cr deficiency but also affected by the molybdenosis. As could be expected, Cu deficiency (groups 1 and 3) caused low levels of caeruloplasmin, secondarily affecting the Fe metabolism in these animals. Protein abnormalities, detected as altered electrophoretic patterns of serum proteins, were also seen mainly in group 3. The findings were also confirmed by multivariate data analysis, where PCA revealed the overall impact of the deficiencies, and PLS regression coefficients indicated the influence on the various analytes.

Experimental copper and chromium deficiency and additional molybdenum supplementation in goats I. Feed consumption and weight development

Secondary Cu deficiency, Cr deficiency and molybdenosis were suggested causes of the ‘mysterious’ disease afflicting moose ( Alces alces L.) in a region in south-west Sweden affected by acid rain. A model experiment with goats was performed to study the clinical chemical parameters, determine the tissue contents of trace and minor elements, to perform pathological and histopathological investigations and to compare the findings with those in moose disease. Twenty 3-month-old male goats were assigned to four dietary treatments (five animals each) in an experiment lasting for 20 months. The four groups in the study were: control group, Cu-deficient group (group 1), Cr-deficient group (group 2), and Cu- and Cr-deficient group (group 3). The animals were fed a basic semi-synthetic diet. At the end of the study the three surviving animals of group 3 were supplemented with additional tetrathiomolybdate (TTM) during the last 2 months. Feed consumption and weight development of the animals were monitored and are presented. The feed consumption of the two Cu-deficient groups of goats (group 1 and group 3) supported the previously described observations in copper deficiency in ruminants, e.g. decreased appetite and feed intake. A previously unreported effect of Cr deficiency in ruminants is now described in goats. Chromium deficiency at adequate Cu supplementation (group 2), caused increased lipid synthesis and a weight gain of 32 kg compared with that of the control group (20 kg). A possible explanation for this unexpected weight increase in only Cr deficiency is discussed. It is concluded that the feeding experiment does not support the hypothesis concerning the relation of Cr deficiency to the moose disease.

An iron-deficient diet stimulates the onset of the hepatitis due to hepatic copper deposition in the Long-Evans Cinnamon (LEC) rat.

To study effects of dietary Cu and Fe levels on the onset of hepatitis in Long-Evans Cinnamon (LEC) rats, female rats (40 days old) were fed a semipurified diet containing 0.1 or 10 mg Cu/kg and 1.5 or 150 mg Fe/kg in a 2 x 2 factorial arrangement for 35 days. At 75 days after birth, LEC rats (+Cu-Fe) fed a Cu-sufficient but Fe-deficient diet (Cu, 10 mg/kg; Fe, 1.5 mg/kg) showed jaundice, with lethargy, anorexia, and malaise. The biochemical variables relating to liver function were significantly increased compared to three other groups, a Cu- and Fe-deficient (-Cu-Fe) group, a Cu-deficient but Fe-sufficient (-Cu+Fe) group, and a Cu and Fe sufficient (+Cu+Fe) group. Furthermore, the +Cu-Fe rat liver showed massive necrosis with huge nuclei. The other three groups presented no biochemical and histological findings of hepatitis. Hepatic Cu and metallothionein concentrations were 289 +/- 87 (mean +/- SD) microg/g liver and 8.7 +/- 1.8 mg/g liver, respectively, in the +Cu-Fe rats. However, in the +Cu+Fe group the values were 196 +/- 28 microg Cu/g liver and 10.8 +/- 1.0 mg/g liver. Hepatic Fe deposition was not influenced significantly by the dietary Cu level. The +Cu-Fe group with jaundice showed the highest free Cu concentration in the liver among the four groups, but the hepatic free Fe concentration was similar to those in the -Cu+Fe and +Cu+Fe groups. Our results indicate that an Fe-deficient diet enhances the deposition of hepatic Cu due to increased absorption of Cu from the gastrointestinal tract. This deposition stimulated the onset of hepatitis.

Alterations of Rat Brain Peptidylglycine -Amidating Monooxygenase and Other Cuproenzyme Activities Following Perinatal Copper Deficiency

Perinatal copper (Cu) deficiency was studied in month-old female and male Sprague-Dawley rat offspring to investigate regional changes in brain cuproenzymes. Offspring of dams given the low Cu treatment beginning at Day 7 of gestation exhibited signs characteristic of Cu deficiency including a 70% reduction in liver Cu levels compared with Cu-adequate controls. Compared with Cu-adequate rats, Cu-deficient rats had lower activities of the cuproenzymes peptidylglycine alpha-amidating monooxygenase (PAM), cytochrome c oxydase (CCO), and Cu,Zn-superoxide dismutase (SOD) in all six brain regions studied. Apparent activity of dopamine-beta-monooxygenase (DBM) was higher in all regions from Cu-deficient compared with Cu-adequate rats. Activity of the selenoenzyme glutathione peroxidase (GPX) was not greatly altered in brain by Cu deficiency. Following 1 month of Cu repletion, liver but not brain Cu levels were equivalent to control. Brain CCO activity was still lower in Cu-repleted female and male rats. PAM activity was still lower in cerebrum of Cu-repleted rats. DBM activity was no longer significantly elevated in the former Cu-deficient groups except for midbrain. SOD and GPX activity were equivalent between groups. PAM activity, in vitro, is lower in the brain following perinatal Cu deficiency and activity is slow to recover following nutritional supplementation with Cu. Perhaps neuropeptide maturation is compromised by Cu deficiency.

Effects of Copper Status on Neutrophil Function, Superoxide Dismutase, and Copper Distribution in Steers

Twelve Holstein steers in a completely randomized block design were fed either a basal diet (concentrate:silage or hay at a DM ratio of 35:65) plus Cu sulfate at 20ppm of Cu (Cu-supplemented diet) or a basal diet plus ammonium molybdate to obtain 10ppm of Mo (Cu-depleting diet) on a DM basis in the whole diet for 8 mo. Supplemental Mo was utilized in the Cu-depleting diet to develop a Cu-deficient group. Molybdenum slowly accumulated in the liver in the group fed the Cu-depleting diet. Copper concentrations in the liver and polymorphonuclear neutrophils decreased in the Cu-deficient group compared with the Cu-sufficient group. Plasma Cu concentration did not change during the trial for the Cu-sufficient group. In the Cu-deficient group, plasma Cu concentrations increased during the first 3 mo of the trial, then declined, and remained unchanged for the last 5 mo. Superoxide dismutase activities in red blood cells, polymorphonuclear neutrophils, and whole blood decreased in the Cu-deficient group. Phagocytic capacity was not affected by Cu status, but killing capacity was decreased by low Cu status in the Cu-deficient group by the end of the trial. Glutathione peroxidase activity was unaffected by Cu status. Clinical symptoms of Cu-deficiency were not observed in this trial; there was no evidence of blood hemoglobin or BW gain difference between the two groups. In this study, Cu status affected its distribution in the tissues and related enzyme activities as well as bactericidal function of neutrophils.

Increased Lung Copper-Zinc-Superoxide Dismutase Activity and Absence of Magnetic Resonance Imaging-Detectable Lung Damage in Copper-Deficient Rats Exposed to Hyperoxia

The effects of hyperoxia on physiological responses, pathological lung lesions detected noninvasively by proton magnetic resonance imaging (MRI), and the oxygen free radical defense enzymes were measured in Cu-deficient rats. Exposure to 85% oxygen seemed to impose a stress on the whole animal as indicated by two physiological responses, decreased food intake and decreased body weight of ad libitum-fed rats. However, all rats exposed to 85% oxygen, including the Cu-deficient group, were able to survive 1 wk of hyperoxia exposure. The target organ specificity for hyperoxia exposure was in the lung as indicated by the increased lung:body weight ratio in all hyperoxia-exposed rats regardless of dietary treatment. All dietary treatment groups exposed to hyperoxia had a similar increase in lung:body weight ratio, but none of the hyperoxia-exposed rats had MRI-detectable lung damage. After 7 d of hyperoxia exposure, all dietary treatment groups, including the Cu-deficient rats, had increased activity of lung CuZn-superoxide dismutase (CuZnSOD), but changes in CuZnSOD activity were not related to lung Cu or Zn concentrations. We propose that the ability to increase CuZnSOD activity is the most important factor of the enzymatic oxygen free radical defense system for protection against hyperoxia-induced lung damage detected by MRI. Even though lung Cu concentration was decreased in Cu deficiency, it seems that Cu-deficient rats are still able to increase lung CuZnSOD activity in response to 85% oxygen exposure.

Specific binding and uptake of apolipoprotein E-free high density lipoproteins by cultured liver parenchymal cells of copper-deficient rats

The influence of copper deficiency on the binding and uptake of apolipoprotein E-free high density lipoprotein (apo E-free HDL) in cultured rat hepatic parenchymal cells was examined in this study. Male weanling Sprague-Dawley rats were randomly divided into two treatments, a Cu-adequate (7.33 mg Cu/kg diet) or a Cu-deficient (1.04 mg Cu/kg diet) group. After 7 weeks, plasma apo E-free HDL were isolated by a combination of ultracentrifugation, gel filtration, and heparin-Sepharose affinity chromatography. Parenchymal cells were isolated from collagenase perfused liver of Cu-deficient and adequate rats and cultured for 16 hours at 37°C prior to incubation with iodinated apo E-free HDL from the same treatment group. Cells were incubated with 5 μg/ml 125 I-apo E-free HDL for 2, 6, or 12 hours in the presence or absence of 200 μg/ml (40-fold) excess unlabeled apo E-free HDL. Increases in specific binding at 4°C and specific cell-associated uptake at 37°C as a function of time were observed with cells and HDL from Cu-deficient rats. Cells were also incubated for 6 hours with 8 concentrations of 125I-apo E-free HDL in the presence or absence of excess unlabeled HDL. Although no significant increase in specific binding was detected at 4°C as a function of ligand concentration, the response tended to be higher at 5 to 15 μg HDL/ml for the Cu-deficient treatment. However, at 37°C the specific cell-associated uptake was increased markedly with cells and HDL from Cu-deficient rats. The observed increases in HDL binding and uptake indicate that these processes may be enhanced in Cu-deficient rats. These data are also consistent with recent in vivo results which indicate that plasma clearance and tissue uptake of HDL are increased in Cu-deficient rats.

Consequences of copper deficiency are not differentially influenced by carbohydrate source in young pigs fed a dired skim milk-based diet

Carbohydrates (CHO) such as fructose (FR) or sucrose, but not starch (ST), aggravate the consequences of dietary copper (Cu) deficiency in rats. To evaluate whether this Cu X CHO interaction is pertinent to human health, the pig was used as an animal model. In two studies, 66 weanling pigs were fed dried skim milk (DSM)-based diets for 10 wk with 20% of the total calories provided as either FR, glucose, or ST and containing either deficient (1.0-1.3 micrograms/g diet) or adequate (7.1 micrograms/g) levels of Cu. Plasma and tissue levels of Cu, the activities of plasma ceruloplasmin ferroxidase and erythrocyte Cu, Zn-superoxide dismutase, and hematocrits were lower (p less than 0.05) in animals fed Cu-deficient diets. The relative cardiac mass of all Cu-deficient groups was greater (p less than 0.05) than that of animals fed Cu-adequate diets. These effects were in general unaffected by type of CHO. For comparison, weaned male rats were also fed DSM-based containing diets ST or FR with adequate or deficient Cu for as long as 10 wk. Rats consuming the Cu-deficient diets were characterized by significantly lower hematocrits, decreased tissue Cu levels, and enlarged hearts, regardless of the CHO source. Together, these data demonstrate that DSM-based diets are not suitable for delineation of potential Cu X CHO interactions, and one or more components of DSM may exacerbate the consequences of dietary Cu deficiency.

Dietary saturated or polyunsaturated fat and copper deficiency in the rat

Dietary fat-type and copper (Cu) deficiency have been independently identified as potentially important factors in the etiology of ischemic heart disease (IHD); a disease that has been linked to inflammation and oxygen free radical (OFR) mediated damage. Group (n = 6) of male, weanling, Wistar rats were provided ad libitum with deionized water and control or low Cu diets containing (200 g/kg) either saturated or polyunsaturated fatty acids (SFA or PUFA, respectively) for 56 d. Measurement of several indices of Cu status indicated that both groups fed the low Cu diets were Cu-deficient. SFA consumption resulted in significantly increased hepatic Cu (p less than 0.001) and iron (Fe) (p less than 0.001) concentrations and xanthine oxidase activity (p less than 0.05) and significantly decreased hepatic glucose-6-phosphate dehydrogenase activity (p less than 0.001). Although Cu deficiency resulted in significantly decreased hepatic copper-zinc superoxide dismutase (CuZnSOD) activity (p less than 0.01), no significant effect on the activities of the other hepatic antioxidant enzymes, manganese superoxide dismutase, catalase, and glutathione peroxidase, or glutathione reductase, were observed. Cu deficiency also resulted in significantly decreased hepatic Cu levels (p less than 0.001) and cytochrome c oxidase activity (p less than 0.01). No significant difference in hepatic thiobarbituric acid reactive substances (TBARS), a measure of lipid peroxidation, was found between groups consuming SFA or PUFA, but both Cu-deficient groups exhibited significantly increased hepatic TBARS (p less than 0.001), compared to controls. This was probably owing to the significantly decreased hepatic CuZnSOD activity observed in the Cu-deficient, compared to control animals.

Superoxide dismutase activity in lung from copper- and manganese-deficient mice exposed to ozone

Nutritional manganese (Mn) or copper (Cu) deficiency was investigated in Swiss-Webster mice exposed to ozone (O 3). Mice rendered Mn-deficient were first reared from Mn-deficient dams and then fed a Mn-deficient (1 μg/g) diet. Mice rendered Cu-deficient were fed a diet containing 0.2 μg Cu/g diet. Control mice were fed a diet containing Mn at 45 μg/g and Cu at 8 μg/g. During the last week of the experiment (week 7, post-weanling), mice in each group were exposed continuously to 1.2 ppm O 3 or filtered air for 7 days. Superoxide dismutase (SOD) activity in lung was then estimated. In mice breathing filtered air, neither lung Cu,Zn- nor Mn-SOD activity (U/g) was affected by diet. In O 3-exposed mice, howver, Mn-SOD activity was lower in the Mn-deficient group and Cu,Zn-SOD activity was lower in the Cu-deficient group. Moreover, total lung Cu,Zn-SOD activity was elevated in the Mn-deficient mice, whereas total Mn-SOD activity was elevated in the Cu-deficient mice in response to O 3. These data indicate that under normal circumstances lung Cu,Zn-SOD and Mn-SOD are not affected by Cu or Mn deficiency. However, when an oxidant stress is superimposed on the Cu- or Mn-deficient condition, Cu,Zn- and Mn-SOD activities are impaired.

Copper deficiency impairs growth of infants recovering from malnutrition

To evaluate the effect of copper deficiency on growth in humans we performed a prospective case-control study in 11 infants identified as Cu deficient based on low plasma Cu (less than 70 micrograms/dL [11.0 mumol/L]) and low ceruloplasmin (less than 200 mg/L). Growth was evaluated with anthropometric indices 1 mo before and 1 mo after onset of Cu supplementation of 80 micrograms.kg-1.d-1. Plasma Cu and ceruloplasmin rose significantly after 1 mo of supplementation. Weight-for-age and weight-for-length indices increased significantly after supplementation only in the Cu-deficient group. Daily energy intake was significantly higher in the Cu-deficient group after supplementation than it was in the control group. Daily weight gain after supplementation increased significantly in the Cu-deficient group and the value for daily weight gain after supplementation was significantly higher than that of the control group for the equivalent amount of time. Cu supplementation improves the growth of Cu-deficient infants recovering from malnutrition.