Absent effect of zinc deficiency on the oxidative stress of erythrocytes in chronic uremic rats

Both anemia and zinc deficiency are commonly observed in patients with chronic uremia. Oxidative stress of red blood cells (RBC) has been suggested to participate in the development of anemia in these patients with chronic uremia due to reduced life span of RBC. Whether zinc deficiency aggravates the effect of oxidative stress on RBC of chronic uremia is still not understood. We thus performed the study to determine the influence of zinc deficiency on the oxidative stress of RBC in uremic rats. Zinc deficiency was induced by long-term dietary zinc deficiency. Five-sixth nephrectomy (5/6 Nx) was used to produce chronic uremia. Experiment was carried out in the following five groups: normal control (NL), chronic uremia (Nx), chronic uremia + dietary zinc deficiency (Nx-D), Nx-D + zinc supplement (Nx-DZ) and Chronic uremia + pair-fed (Nx-PF). Osmotic fragility and lipid peroxidation of RBC were used to evaluate the oxidative stress of RBC. Five weeks after 5/6 nephrectomy (Nx), 5/6 Nx rats present a syndrome of uremia to elevate the levels of plasma creatinine and urea, and reduce the level of plasma zinc (1.12 +/- 0.08 vs 1.35 +/- 0.05 ug/ml). But they does not find to produce anemia and to increase osmotic fragility and lipid peroxidation in RBC. Dietary zinc deficiency in Nx-D group produced severe anorexia and reduced plasma zinc and selenium levels and the activity of RBC-GPX. Yet in Nx-D rats, osmotic fragility and susceptibility of lipid peroxidation in red cells did not increase, because of the increase of plasma copper level (1.85 +/- 0.3 vs 1.41 +/- 0.05 microg/ml) and RBC-SOD activity (1.95 +/- 0.27 vs 0.78 +/- 0.05 unit/g Hb). Zinc supplement in Nx-D rats (Nx-DZ group) recovered the appetite and normalized the levels of plasma zinc, copper and selenium. Food restriction in 5/6 Nx rats (Nx-PF group) decreased plasma copper level and increased osmotic fragility of RBC and elevated the susceptibility of lipid peroxidation after stressing RBC with H2O2 Because Nx-PF rats presented a lower RBC-SOD activity (0.44 +/- 0.11 vs 0.78 +/- 0.05 unit/g Hb) and a lower plasma copper level. We further found a positive relationship (r=0. 802,p<0.01) between plasma copper level and RBC-SOD activity in normal and uremic rats. This study suggests that RBC-SOD activity may play an important role in preventing RBC oxidative stress. Plasma copper level may be a marker of RBC-SOD activity. We conclude, in chronic uremia, zinc deficiency doses not result in RBC oxidative stress as plasma copper level is normal, but may affect the absorption of intestinal nutrition.     

Indices of iron and copper status during experimentally induced,marginal zinc deficiency in humans

This study examined the effect of diet-induced, marginal zinc deficiency for 7 wks in 15 men (aged 25.3 +/- 3.3 yrs; mean +/- SD) on selected indices of iron and copper status. The regimen involved low-zinc diets based on egg albumin and soy protein with added phytate and calcium such that mean [phytate]/[Zn] and [phytate] X [Ca]/[Zn] molar ratios were 209 and 4116, respectively, for 1 wk, followed by 70 and 2000, respectively, for 6 wks. Subjects were then repleted with 30 mg Zn/d for 2 wks. Plasma copper, Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activity in plasma and red blood cells (RBC), hemoglobin, hematocrit, and serum ferritin were determined weekly on fasting blood samples. Significant reductions (p less than 0.05) after 7 wks in RBC Cu,Zn-superoxide dismutase (49.5 +/- 7.2 vs 33.6 +/- 6.3 U/mg Hb) and serum ferritin (69.2 +/- 38.7 vs 53.8 +/- 33.7 micrograms/L) occurred; no comparable decline was noted for plasma Cu, hemoglobin, or hematocrit. Significant (p less than 0.05) but less consistent changes were also observed in plasma superoxide dismutase activity. None of the changes were associated with the decreases in plasma, urinary and hair zinc concentrations, and alkaline phosphatase activity in RBC membranes. Results indicate that the biochemical iron and copper status of the subjects was marginally impaired, probably from the dietary regimen that induced marginal zinc deficiency.     

Prevalence of zinc deficiency in junior high school students of Tehran City

Zinc deficiency is a health problem in many communities especially among adolescents because of pubertal growth sprout. This investigation was carried out to determine the epidemiology of zinc deficiency in junior high school students in Tehran City in 1997. This cross-sectional study was performed on 881 students (452 males and 429 females) with the mean age of 13.2±1.0 yr, who were selected by multistage random sampling method. Plasma, erythrocyte, and hair zinc levels were assayed by flame atomic absorption spectrophotometry. Anthropometric and demographic characteristics were measured and recorded on a questionnaire. Dietary intakes were evaluated by a 24-h recall method. Zinc deficiency was defined as having at least two indices from indices of erythrocyte, plasma, and hair zinc below 10 μg/mL, 100 μg/dL, and 125 μg/g of hair, respectively. The results showed that zinc deficiency prevalence was 31.1% (confidence interval: 28–34.4%). Zinc deficiency was 65%, 49%, and 1.3% based on plasma, erythrocyte, and hair zinc levels, respectively. The mean ± SD for plasma, erythrocyte, and hair zinc concentration, height-for-age, as well as weight-for-age Z scores were 95.2±17.7 μg/dL, 10.3±2.3 μg/mL, 239.4±54.4 μg/g, −0.40±0.92, and 0.12±0.91, respectively. As for dietary intake compared with the RDA, 50% of the subjects consumed less than 50% of their requirement for zinc RDA based on a 24-h dietary recall. Zinc intake in subjects was 7.5±3.7 μg, that in boys was higher than in girls. Correlation coefficients between zinc status indices were very weak. There was neither a linear nor nonlinear relationship between biochemical parameters and nutritional zinc intake. It is concluded that almost one-third to one-half of the subjects would be considered zinc deficient.     

Lead levels in some biological samples of auto-mechanics in Abeokuta, Nigeria

Lead levels were determined in the blood, scalp hair and fingernails of 38, all male auto-mechanics (aged 18-45 years) from Abeokuta, South-western Nigeria. The subjects were classified into four sub-groups based on the period of exposure namely: 1-5, 6-10, 11-15, and >16 years. Thirty-two occupationally unexposed subjects (mainly office workers) served as the control. The weight, height and body mass indexes of all subjects were noted, in addition to other information obtained through structured questionnaire. The mean values of blood lead (BPb), hair lead (HPb) and fingernail lead (NPb) of the occupationally exposed subjects (n=38) were 48.50 +/- 9.08 microg/dL, 17.75 +/- 5.16 microg/g, and 5.92 +/- 3.30 microg/g respectively, while the corresponding mean values for these parameters in the control subjects (n = 32) were 33.(,5 +/- 10.09 microg/dL, 14.30 +/- 5.90 microg/g and 5.31 +/- 2.77 microg/g respectively. The differences in BPb and HPb levels of the two groups were statistically significant (P <0.05 and P <0.01 respectively), while that of NPb was not significant. The levels of lead in the biological samples appeared to have no relationship with the number of years on the job. From these results, it was obvious that the higher levels of lead in the biological samples of test subjects, compared with those of the controls were from environmental sources.     

Growth hormone deficiency: permanence and diagnosis in young adults

OBJECTIVE: To optimize the tools for diagnosing idiopathic growth hormone (GH) deficiency. METHODS: We compared the data of 43 young adults treated for GH deficiency before and after GH treatment and puberty. Those with organic lesions were assigned to group 1 (n = 9), those with certain GH deficiency (n = 11) to group 2 and those with no criterion of certitude of GH deficiency to group 3 (n = 23). RESULTS: Group 1 patients: the GH peaks at first [1.5 +/- (SE) 0.4 microg/l] and second (1.9 +/- 0.7 microg/l) evaluations before treatment were similar to those at the third evaluation (1.2 +/- 0.8 microg/l) after treatment. Group 2 patients: they had similar peaks (2.6 +/- 0.8, 2.9 +/- 0.5 and 5.5 +/- 1.4 microg/l). Group 3 patients: the peaks increased from 4.9 +/- 0.4 and 4.8 +/- 0.4 to 18.4 +/- 2.3 microg/l (p < 0.0001); 87% had a GH peak >10 microg/l at this evaluation. The plasma insulin-like growth factor 1 was initially below -2 z-score in 12/13 of these patients and similarly low in 4/17 patients at the third evaluation. The growth rates of the three groups before and their increase during the 1st year of treatment were similar. CONCLUSION: Almost all patients with GH deficiency before puberty without criteria of certitude had a normal GH peak after puberty. Some of these patients probably had a transiently low GH secretion.     

Plasma selenium status in children with iron deficiency anemia

Iron and selenium are trace elements necessary for the maintenance of life and health. Iron deficiency is the most common nutritional deficiency among children in the world. The purpose of this study was to evaluate plasma selenium concentrations in children with iron deficiency anemia (IDA). Plasma selenium levels were investigated in 56 children with IDA and in 48 control subjects aged 1-8 years. A spectrofluorometric method was used for the determination. Plasma selenium concentrations in children with IDA (33.6+/-8.2 microg/l) were significantly lower than in the control group (56.0+/-17.0 microg/l) (p<0.001). However, there was no relation between plasma selenium, iron and hemoglobin concentrations.     

Should chronic obstructive pulmonary disease outpatients be routinely evaluated for trace elements?

We searched for serum concentrations of trace elements and correlated them to malondialdehyde (MDA), which is an indirect marker of oxidative stress, in order to clarify if routine evaluation is necessary in chronic obstructive pulmonary disease (COPD) outpatients. Serum concentrations of copper (Cu), zinc (Zn), and magnesium (Mg) were determined by atomic absorption spectrophotometry and iron (Fe) by a ILLab 1800 autoanalyzer with ILLab test kits. Serum MDA concentrations were detected in terms of TBARS (thiobarbituric acid reactive substances) spectrophotometrically. Serum Cu, Zn, Mg, Fe, and MDA concentrations in patient and control groups were all in the normal reference range. The results respectively were as follows: Cu:123±29.2 and 122.2±23.4 μg/dL; Zn: 87.8±17.8 and 96.9 ± 12.9 μg/dL; Mg: 2.3±0,5 and 2.04±0.28 mg/dL; Fe: 73.8±35.5 and 80.7±51.2 μg/dL; MDA: 1.09±0.11 and 0.95±0.06 nmol/L. MDA was not correlated to Cu, Zn, Mg, or Fe (p>0.05 for all). The serum Zn concentration of COPD group was lower than the control group (p=0.042), whereas the Mg concentration was higher (p=0.021). There was no statistical difference in other study parameters. Oxidative stress was not increased in clinically stable, regularly treated COPD patients. Although there was no deficiency in trace elements (Cu, Fe, Mg, and Zn), serum Zn was close to the lower limit of the reference value. There is no need for routine evaluation of trace elements in clinically stable, regularly treated COPD outpatients.     

Serum trace elements status of rabbits supplemented with Nigella sativa,vitamins C and E,and selenium against damage by N-methyl-N'-nitro-N-nitrosoguanidine

In this study, we investigated the effects of Nigella sativa, vitamins C and E, and selenium on the levels of trace elements in the serum of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-injected rabbits. The rabbits were separated into one control and three experimental groups, each consisting of eight rabbits. MNNG was administered to all rabbits at a dose of 20 mg/kg. Group A received a suspension of N. sativa, group B received a combination of vitamins C and E and selenium, and group C received MNNG without any additional treatment. Group D did not receive any treatment and acted as control. The concentrations of serum zinc, copper, and iron were determined for groups A, B, C, and D. The zinc levels were 155.3±25.8, 304.7±14.22, 117.2±27.9, and 87.0±8 μ/dL for groups A-D, respectively; copper was measured at 234.8±31.9, 214.3±14.2, 196.5±19.3, and 359.2±19.9 μ/dL and iron levels were 276.3±10.71, 260.8±7.15, 211.2±13.47, and 223.4±9.5 μ/dL, in the stated group order. There were statistically significant differences between groups (p<0.05). The results obtained in this work may be of use for monitoring and preventing the nocive effects of N-methyl-N′-nitro-N-nitrosoguanidine and similar carcinogens.     

Correction of a mouse model of Menkes disease by the human Menkes gene

The brindled mouse is an accurate model of the fatal human X-linked copper deficiency disorder, Menkes disease. Males carrying the mutant allele of the Menkes gene orthologue Atp7a die in the second week of life. To determine whether the genetic defect in the brindled mice could be corrected by expression of the human Menkes gene, male transgenic mice expressing ATP7A from the chicken beta-actin composite promoter (CAG) were mated with female carriers of the brindled mutation (Atp7a(Mo-br)). Mutant males carrying the transgene survived and were fertile but the copper defect was not completely corrected. Unexpectedly males corrected with one transgenic line (T25#5) were mottled and resembled carrier females, this effect appeared to be caused by mosaic expression of the transgene. In contrast, males corrected with another line (T22#2) had agouti coats. Copper concentrations in tissues of the rescued mutants also resembled those of the heterozygous females, with high levels in kidney (84.6+/-4.9 microg/g in corrected males vs. 137.0+/-44.3 microg/g in heterozygotes) and small intestine (15.6+/-2.5 microg/g in corrected males vs. 15.7+/-2.8 microg/g in heterozygotes). The results show that the Menkes defect in mice is corrected by the human Menkes gene and that adequate correction is obtained even when the transgene expression does not match that of the endogenous gene.     

Elevated serum copper levels in women with a history of post-partum depression.

Previous observations suggested that there may be an association between elevated serum copper (Cu) levels and post-partum depression (PPD). In this study, we examined Zn and Cu levels in women with completed pregnancies who had a history of PPD and compared them to women who did not have depression, and to women who reported having been depressed, but without a history of PPD. Cu levels were significantly higher in women having a history of PPD compared both to non-depressed women and to depressed women without a history of PPD. The mean serum Cu level of 78 women with a history of PPD was 131+/-39microg/dL compared with 111+/-25microg/dL in 148 women without such a history, and 106+/-20microg/dL in non-depressed controls (p<0.001). Zn levels did not differ across the three groups. Cu/Zn ratios were significantly higher in the PPD-history-positive group, due to the significant differences in Cu levels. Cu and Zn levels were not significantly different in depressed and non-depressed men, nor between non-depressed women and non-depressed men. Depressed women had higher Cu, but not Zn, levels compared with men. The nature of the association between elevated Cu values and PPD is, as yet, unknown; however Cu has roles in a variety of physiological systems that may be implicated in the development of PPD.     

Measurement of hemoglobin synthesis rate in vivo using a stable isotope method

We developed a method to measure hemoglobin synthesis rate (SynHb) in humans, assuming that free glycine in the red blood cell (RBC) represents free glycine in bone marrow for hemoglobin synthesis. The present rat study examines this assumption of the method and quantifies SynHb in rats. Sprague-Dawley rats (n = 9) were studied, [2-(13)C]glycine was intravenously infused over 24 h (2.5 mg kg(-1) h(-1)), blood was drawn for glycine and heme isolation, and bone marrow was harvested for glycine isolation. Isotopic enrichments of glycine and heme were measured, fractional hemoglobin synthesis rate (fSynHb% day(-1)) was calculated, and from this a value for SynHb (mg g(-1) day(-1)) was derived. Mean body weight was 446 +/- 10 g (mean +/- SE) and hemoglobin concentration was 14 +/- 0.5 g dl(-1). At 24 h, the mean isotopic enrichment, atom percentage excess (APE), of the RBC free glycine (1.56 +/- 0.18 APE) was similar to the bone marrow (1.68 +/- 0.15 APE). The rate of incorporation of (13)C into heme increased over time from 0.0004 APE/h between 6 and 12 h, to 0.0014 APE/h between 12 and 18 h, and 0.0024 APE/h between 18 and 24 h. Consequently, fSynHb (1.19 +/- 0.32, 2.92 +/- 0.66, and 4.22 +/- 0.56% day(-1), respectively) and SynHb (0.11 +/- 0.03, 0.28 +/- 0.05, and 0.42 +/- 0.05 mg g(-1) day(-1), respectively) showed similar patterns over the 24-h study period. We conclude that (1) enrichment of free glycine in the circulating RBC approximates enrichment of bone marrow free glycine for heme formation and (2) this pattern of hemoglobin synthesis rate is reflecting the characteristic release and gradual maturation of reticulocytes in the circulation.     

Associations between Serum C-reactive Protein and Serum Zinc, Ferritin, and Copper in Guatemalan School Children

Inflammation affects trace nutrient concentrations, but research on copper and particularly in children is limited. We assessed associations between serum C-reactive protein (CRP) and zinc, iron, copper, and other biomarkers (alkaline phosphatase, hemoglobin, and albumin), in 634 healthy 6- to 11-year-old Guatemalan schoolchildren. CRP was measured by a standardized, high-sensitive method. For significant associations with CRP, we stratified nutrient concentrations across categories of CRP and compared concentrations above and below several CRP cutoff points (0.5, 1, 3, 5, and 10 mg/L), and then adjusted values using correction factors (ratios of geometric means of the nutrients in the low and high groups). Prevalence of serum zinc (<65 μg/dL0, ferritin (<15 μg/L), and copper (<90 μg/dL) deficiency were 21%, 2.1%, and 23.8%, respectively. Median (25th and 75th percentiles) CRP was 0.56 (0.26 and 1.54) mg/L. CRP concentration was positively associated with ferritin and copper concentrations (r = 0.23 and 0.29, respectively; P < 0.0001) but not with zinc and other biomarkers (P > 0.05). Regardless of CRP cutoffs, high (> cutoff) vs. low (≤ cutoff) CRP levels had higher ferritin and copper concentrations and lower prevalence of copper deficiency of <90 μg/dL (P < 0.05). Adjustment for inflammation had the greatest influence on recalculated prevalence for the CRP 0.5 mg/L cutoff. The low ferritin prevalence hardly changed (from 2.1% to 2.5%) while the low copper prevalence changed appreciably (from 23.8% to 31.2%). In conclusion, CRP was positively associated with ferritin and copper but not with zinc concentrations. Adjustment for inflammation had little effect on low ferritin prevalence, low to begin with, and a large impact on low copper prevalence. High-sensitive CRP methods and the use of very low CRP cutoffs may be more accurate than traditional CRP methods in the adjustment of serum copper concentrations for inflammation in healthy school children.     

Increased serum copper and decreased serum zinc levels in children with iron deficiency anemia

In order to evaluate serum copper and zinc status in children with iron deficiency anemia (IDA), 60 children with IDA aged 1–14 yr and 64 healthy children as controls aged 1–14 yr were included the study. Serum copper levels were higher in children with IDA (189 ± 49 (Μg/dL) than those of controls (163 ± 37 Μg/dL) (p = 0.001). Serum zinc levels were lower in the patient group (109 ± 59 Μg/dL) than those of control subjects (135 ± 56 Μg/dL) (p = 0.017). In addition, there were statistically significant negative correlations between hematological parameters and serum copper levels in the patient group, but not in controls. No correlation between hematological parameters and serum zinc levels were found in both patient and control groups, except positive correlation between mean corpuscular volume (MCV) and serum zinc level in patients. It was concluded that at the time of managing children with IDA, zinc deficiency must be borne in mind and if necessary treatment should be initiated with zinc.     

Plasma and erythrocyte lipid peroxide levels in workers with occupational exposure to lead

The plasma and erythrocyte lipid peroxide levels were measured in a group of male subjects occupationally exposed to lead for an average period of 17 yr, and compared to those from an age-matched control group living in the same city in a similar socioeconomical environment. The blood lead and plasma zinc levels were measured by atomic absorption spectroscopy. The plasma and erythrocyte lipid peroxide levels were established by the malondialdehyde determination method. Significant differences were found in the blood lead levels in lead-exposed workers, 15.00±10.15 μg/dL as compared to controls, 2.37±0.89 μg/dL. The plasma (2.67±0.69 μM) and erythrocyte (27.53±6.28 nmol/g Hb) lipid peroxide levels in workers with occupational exposure to lead were significantly higher than controls, 1.23±0.61 μM and 14.35±2.08 nmol/g Hb, respectively. There were no significant differences of the zinc levels in both groups. The blood lead levels had a statistically significant positive correlation with age and with duration of exposure in both groups, but showed no relationship to the corresponding blood zinc levels. The results presented in this study indicate that the increase of plasma and erythrocyte lipid peroxide levels in workers exposed to lead may be related to the lead concentration, age and duration of exposure.     

Alzheimer病患者APP及PS1基因表达量的研究

为了检测Alzheimer病（Alzheimer’s disease,AD）患者外周血中淀粉样前体蛋白（Amyloid Precursor Protein, APP）基因及早老素1（Presenilin 1, PS1）基因的表达情况,进而探讨APP及PS1基因的表达与AD的相关性,采用SYBRGreenⅠ的方法对45例AD患者、25例血管性痴呆（vascular dementia, VD）患者及60名正常对照组样本的mRNA进行绝对定量,检测得到APP基因及PS1基因在对照组中的表达水平分别为0.026±0.005 amol/μg cDNA和0.026±0.004 amol/μg cDNA;在AD患者组中的表达量分别为0.044±0.006 amol/μg cDNA和0.051±0.011 amol/μg cDNA;,在VD患者组中的表达水平分别为0.072±0.013 amol/μg cDNA和0.039±0.005 amol/μg cDNA 。经显著性检验,AD患者组APP基因的表达水平上调,t=2.639, P<0.01;PS1基因的表达水平同样呈上调趋势,t=2.173,P<0.05,差异均具有统计学意义。VD患者组APP基因的表达水平上调,t=3.028,P<0.01;PS1基因的表达水平也同样呈上调趋势,t=2.012,P<0.05,均有显著性差异。因此,APP及PS1基因的表达水平的增高并不一定与AD发生特异性关联,而可能与多种导致痴呆的脑部病变发生关联。     

Determination of total aluminum, chromium, copper, iron, manganese, and nickel and their fractions leached to the infusions of black tea, green tea, Hibiscus sabdariffa, and Ilex paraguariensis (mate) by ETA-AAS

Total aluminum, chromium, copper, iron, manganese, and nickel were determined in black tea, green tea, Hibiscus sabdariffa, and Ilex paraguariensis (mate) by electrothermal atomic absorption spectrometry after nitric/perchloric acid digestion. In each case, one ground sample of commercially available leafy material was prepared and three 0.5-g subsamples were run in parallel. The infusions were also analyzed and the percentage of each element leached into the liquor was evaluated. The obtained results indicated that hibiscus and mate contained lower levels of aluminum (272±19 μg/g and 369±22 μg/g, respectively) as referred to black tea (759±31 μg/g) or green tea (919±29 μg/g) and suggested that mate drinking could be a good dietary source of essential micronutrient manganese (total content 2223±110 μg/g, 48.1% leached to the infusion). It was also found that the infusion of hibiscus could supply greater amounts of iron (111±5 μg/g total, 40.5% leached) and copper (5.9±0.3 μg/g total, 93.4% leached) as compared to other infusions. Moreover, it was found that the percentage of element leached to the infusion was strongly related to the tannins content in the beverage (correlation coefficients >0.82 with the exception for nickel); for lower tannins level, better leaching was observed.     

Trace Element Levels in Hashimoto Thyroiditis Patients with Subclinical Hypothyroidism

The present study was conducted to evaluate the serum copper, zinc, magnesium, and selenium levels in patients with subclinical hypothyroidism in the iodine-rich region of Ankara, Turkey. The effects of hormone replacement therapy on these elements were also studied in these patients. Basal levels of selenium and iron in patients were significantly lower than control group (67.7 +/- 10.4 vs. 83.7 +/- 17.3 microg/dl, p = 0.02; 55.7 +/- 38 vs 275.7 +/- 24, P = 0.03 microg/dl). Serum magnesium levels were significantly higher in patient group (2.16 +/- 0.31 vs 1.95 +/- 0.13 mg/dl, P < 0.0001). There was a correlation between selenium levels with hsCRP (r = -0.408, p = 0.007). HsCRP levels in patients with selenium levels <80 microg/l (n = 31) was significantly higher than hsCRP levels in patients with selenium levels >80 microg/l (n = 12; 1.99 +/- 1.0; 1.02 +/- 0.9, p = 0.014). None of these biochemical risk factors and trace elements have changed after euthyroidism in patients with SH when compared to pretreatment levels. Selenium deficiency may contribute to cardiovascular disease risk in these patients.     

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.     

Nutritional copper deficiency does not affect sponge granuloma formation in the rat

Sponge granuloma formation was compared in copper-deficient and copper-sufficient rats following feeding of respective diets for 20, 40, or 60 d. Body weight, total blood hemoglobin, and activities of ceruloplasmin and Cu, Zn-superoxide dismutase in plasma were monitored to ascertain copper deficiency. Mean granuloma weights (mg +/- SEM) in copper-deficient and copper-sufficient groups of rats, respectively, were as follows: 37 +/- 2 and 38 +/- 2 after 20 d, 22 +/- 2 and 23 +/- 2 after 40 d, and 19 +/- 1 and 21 +/- 1 after 60 d on respective diets. Thus, nutritional copper deficiency did not have an effect on sponge granuloma formation in the rat.     

Influence of co-administration of oral insulin and docosahexaenoic acid in mice

Insulin and docosahexaenoic acid are both present in human milk. The aim of this study was to examine the effect of co-administration of oral insulin and DHA in mice. Immediately after weaning, Balb C mice were divided into four groups of seven mice each for a period of 4 weeks. Group 1 received a chow diet only. Group 2 received a chow diet and also was given human insulin (1 unit/mL of drinking water) without docosahexaenoic acid. Group 3 received a chow diet supplemented with docosahexaenoic acid (500 mg/kg/day in the chow) and no insulin. Group 4 received a chow diet and supplementation with both human insulin and docosahexaenoic acid. At 28 days, fasting blood levels of glucose, insulin, lipids, lipid peroxidation analysis, docosahexaenoic acid plasma levels, and docosahexaenoic acid content in red blood cells were determined. We found that glucose levels were lower in the group that was supplemented with insulin only (group 2, 61.4 mg/dL +/- 2.8,mean +/- SD) and in the group that was supplemented with DHA only (group 3, 61.1 mg/dL +/- 2.0) compared to controls (group 1, 71 mg/dL +/- 6.9, P < 0.0001). Supplementation of both insulin and docosahexaenoic acid (group 4) resulted in significantly lower glucose levels (56.4 mg/dL +/- 2.6) compared to those in groups 2 and 3 (P < 0.01). No significant differences were found in lipid profile or lipid peroxidation between the groups. We conclude that adding insulin or docosahexaenoic acid to the diet of weaned Balb C mice reduces glucose blood levels. Supplementation with both substances has a synergistic effect. The presence of insulin and docosahexaenoic acid in human milk may be the cause for reduced glucose levels in breast-fed infants, in addition to the known effects of DHA on insulin sensitivity.