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1.
In both cow's milk and human milk, zinc was associated with proteins of high molecular weight (greater than 100 000), as judged by analysis with Sephadex G-75. Precipitation of the casein at pH 4.6 and filtration of the resultant acid whey on Sephadex G-25 led, however, to the recovery of about 90% of the zinc as a compound of low molecular weight, which was tentatively identified as zinc citrate. Over 95% of the zinc of cow's milk was sedimented with the casein micelles on ultracentrifugation. Filtration of these micellar caseins on Sephadex G-150 gave two peaks containing zinc, which corresponded to aggregates of alpha-casein-kappa-casein and of alpha-casein-beta-casein. Ultracentrifugation of human milk sedimented only approx. 40% of total zinc. Analysis of sediment and supernatant on Sephadex G-150, however, indicated that about 85% of the zinc was associated with a protein complex of molecular weight greater than 150 000. The major protein of this complex was identified as lactoferrin. A minor zinc-binding component of average molecular weight 30 000 was also observed in the supernatant. The results indicated that zinc is bound to different macromolecules in cow's and human milk. This may be a factor affecting the bioavailability to the human infant of zinc from the two milks, and it is suggested that in human milk lactoferrin may be involved in the uptake of zinc. 相似文献
2.
Zinc and copper have been estimated in CSF of 14 normal volunteers, nine men and five women. Zinc was analyzed by limited-aspiration
flame atomic absorption spectrophotometry using a deuterium continuum light source. Copper was analyzed in 0.1% HNO3 by flameless atomic absorption spectrophotometry with a graphite cuvette on a flameless atomizer. Recovery of added zinc
varied less than 5% and that of the added copper varied less than 8%. CSF zinc was 31.5±19.8 μg/L (mean ± 1 SD); CSF copper,
7.5±3.1 μ/L. Values obtained for CSF zinc are about 1/2 those we and others obtained previously, the decrease related almost
exclusively to removal of interference by the CSF matrix, which produced spuriously elevated values without use of the deuterium
light source. Values obtained for CSF copper were approximately one-tenth those we and others had obtained previously. The
decrease related, in part, to the removal of matrix effects, but also to improvement of the signal-to-noise ratio present
in other techniques. 相似文献
3.
Gianfranco Vivoli Margherita Bergomi Sergio Rovesti Mirco Pinotti Eva Caselgrandi 《Biological trace element research》1995,49(2-3):97-106
Imbalance of zinc and copper status has been hypothesized in human hypertension. A case-control study was carried out to elucidate the possible relationship between zinc and copper status and essential hypertension. Thirty-one subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 31 normotensive controls individually matched for sex, age, and smoking habits. Zinc and copper in serum and urine were measured, and serum activities of alkaline phosphatase (AP), lactic dehydrogenase (LDH), copper-zinc superoxide dismutase (Cu?Zn SOD), lysyl oxidase (LOX), and monoamine oxidase (MAO) were evaluated. No significant difference in serum and urine zinc and copper content as far as in serum activity of zinc (AP and LDH) or copper (Cu?Zn SOD, LOX, and MAO)-dependent enzymes was found between hypertensives and normotensives. Positive relationships were found in normotensives between serum and urine levels of zinc (r=0.577;p=0.001) and copper (r=0.394;p=0.028), and between serum copper and Cu?Zn SOD (r=0.534;p=0.002). In normotensives, diastolic blood pressure and serum zinc were positively related (r=0.370;p=0.041). In hypertensives, inverse correlations were observed between diastolic blood pressure and AP (r=?0.498;p=0.004) and Cu?Zn SOD (r=?0.452;p=0.011), and between systolic blood pressure and LOX (r=?0.385;p=0.033). Diastolic blood pressure was related to LDH inversely in hypertensives (r=?0.357;p=0.049) and positively in normotensives (r=0.457;p=0.010). In normotensives, diastolic blood pressure was inversely related with MAO (r=?0.360;p=0.046). These findings support the hypothesis that an imbalance of zinc and copper status might be involved in human hypertension. 相似文献
4.
The effectiveness and success of antitubercular therapy is mainly measured by identifying the organism in sputum. In certain
patients, especially in geriatric patients, available tuberculosis tests are not satisfactory and do not provide enough information
on the effectiveness of antitubercular therapy, as the symptoms might be confused with the existing symptoms of ongoing diseases.
Therefore, 60 diagnosed and randomly selected patients with tuberculosis were included into this study. The patients with
other associated diseases likely to influence serum copper and zinc were not included in the study. The estimations of serum
copper and zinc were done in healthy volunteers and in tubercular patients before the start of treatment and after 4 wk of
antitubercular treatment. The average plasma concentration of serum copper and zinc in healthy volunteers were 102±20 μg/dL
and 96±18 μg/dL respectively. In tuberculosis patients, serum copper and zinc levels were 123.65±9.98 μg/dL and 64.14±3.97
μg/dL, respectively, before the start of treatment, which came down to 116.23±4.27 μg/dL and 74.31±3.60 μg/dL, respectively,
after 4 wk of antitubercular treatment. 相似文献
5.
Zinc and copper in the serum of diabetic patients 总被引:2,自引:1,他引:1
Nikica Car A. Car M. Granić Z. Škrabalo B. Momčilović 《Biological trace element research》1992,32(1-3):325-329
The Zn/Cu ratio was examined in the serum of three groups of persons: healthy volunteers, diabetic patients on diabetic diet
(NIDDM), and diabetic patients on diabetic diet and insulin (IDDM). Zinc, copper, the Zn/Cu serum ratio, and the blood glucose
level were determined during fasting and 2 h after breakfast. Zn and Cu serum levels in NIDDM and IDDM patients were decreased.
The Zn/Cu ratio was higher in both groups of diabetic patients. These changes in the Zn and Cu levels as well as in the Zn/Cu
ratio were not related to chronic diabetic complications. 相似文献
6.
Silvestre D Martìnez-Costa C Lagarda MJ Brines J Farré R Clemente G 《Biological trace element research》2001,80(1):1-11
The aim of the study has been to analyze the evolution of copper, iron, and zinc contents in human milk, from colostrum to
the third postpartum month, following a longitudinal design, under specific conditions of sample collection and to apply an
analytical procedure previously optimized to reduce any variation outside physiological lactation.
The copper, iron, and zinc concentrations in 144 milk samples from 39 healthy puerpera women, were analyzed in five stages
by flame atomic absorption spectrometry, following a standardized protocol.
Copper presented a gradual decrease from 0.38 mg/L to 0.19 mg/L by the 90th day; the particular analysis from colostrum to
transitional milk manifested the following two tendencies. Whereas an increase from 0.19 to 0.42 mg/L was observed in some
women, a decrease from 0.53 to 0.45 mg/L was detected in others; therefore, copper presented two significant behaviors in
the evolution from colostrum to transitional milk. In both cases, the evaluated changes were significant. The iron content
varied from 0.56 to 0.40 mg/L by the 30th day, remaining constant until the first trimester concluded. The average zinc concentration
decreased sharply from 7.99 to 3.3 mg/L on d 15; the rate of decrease slowed down gradually until 1.05 mg/L. 相似文献
7.
The zinc and copper content in the different epididymal segments and vas deferens of castrated rats were investigated with the help of atomic absorption spectrophotometer. The vas deferens showed maximum zinc content as compared to that of different parts of epididymis in all groups whether castrated unilaterally, bilaterally or in the intact control. Zinc content was reduced in the epididymis and vas deferens ipsilateral to the castrated side as compared to that of contralateral control and intake animals. Lowest zinc content was observed in the epididymis and vas deferens of bilaterally castrated animals from that of other groups. Absence of sperms was observed in all segments of epididymis and vas in bilaterally castrated animals and from the unilaterally castrated side. Copper content was unaltered in all epididymal segments and vas deferens. There appears to be a correlation between the absence of sperms in the male genital tract and the decrease in zinc content. 相似文献
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10.
Gonzalez BP Niño Fong R Gibson CJ Fuentealba IC Cherian MG 《Biological trace element research》2005,105(1-3):117-134
The effect of dietary zinc (Zn) supplementation on copper (Cu)-induced liver damage was investigated in Long-Evans Cinnamon
rats (LEC), a model for Wilson's disease (WD). Four-week-old LEC (N=64) and control Long-Evans (LE) (N=32) female rats were divided into two groups; one group was fed with a Zn-supplemented diet (group I) and the other was given
a normal rodent diet (group II). LEC rats were killed at 6, 8, 10, 12, 18, and 20 wk of age; the LE control rats were killed
at 6, 12, 18, and 20 wk of age. Cu concentration in the liver was reduced in LEC rats fed the Zn-supplemented diet compared
with LEC rats on the normal diet between 6 and 18 wk of age. Metallothionein (MT) concentration in the livers of LEC rats
in group I increased between 12 and 20 wk of age, whereas hepatic MT concentration in LEC rats from group II decreased after
12 wk. Hepatocyte apoptosis, as determined by TUNEL, was reduced in Zn-supplemented LEC rats at all ages. Cholangiocellular
carcinoma was observed only in LEC rats in group II at wk 20. These results suggest that Zn supplementation can reduce hepatic
Cu concentration and delay the onset of clinical and pathological changes of Cu toxicity in LEC rats. Although the actual
mechanism of protection is unknown, it could be explained by sequestration of dietary Cu by intestinal MT, induced by high
dietary Zn content. 相似文献
11.
F. Martín-Lagos M. Navarro-Alarcón C. Terrés-Martos H. López-García de la Serrana V. Pérez-Valero M. C. López-Martínez 《Biological trace element research》1998,61(1):61-70
A cross-sectional study of serum zinc (Zn) and copper (Cu) levels in 31 healthy pregnant women and 51 healthy, nonpregnant
controls living in the Mediterranean area of Granada, Spain, was performed. The subjects were divided into two groups: Group
A, consisted of pregnant women in three categories according to the trimester of pregnancy, and Group B consisted of nonpregnant
women acting as controls.
In pregnant women, serum Zn levels were found from 0.300-1.340 mg/L and serum Cu from 0.936-2.304 mg/L, whereas in the nonpregnant
women group, the mean serum levels were 0.947 ±0.265 mg/L for Zn and 1.092 ±0.365 mg/L for Cu. Serum Zn progressively decreased
with gestation. Mean Zn levels were 0.829 ±0.253, 0.846 ±0.329, and 0.620 ±0.142 mg/L, corresponding to the first, second,
and third trimesters of pregnancy, respectively.
Serum Zn concentrations were significantly lower in pregnant women as compared to controls: 0.712 ±0.236 mg/L vs 0.947 ±0.265
mg/L, respectively (p < 0.05).
In contrast, Cu levels increased with period of gestation from 1.053 ±0.498 mg/L in the first trimester to 1.616 ±0.304 mg/L
in the second and 1.689 ±0.344 mg/L in the third. Serum Cu levels in the second and third trimesters of pregnancy were significantly
higher (p < 0.05) than those determined during the first trimester and for nonpregnant controls. Both Zn and Cu during pregnancy did
not appear to be dependent on the subject’s age (p > 0.05). 相似文献
12.
Ferahman M Unal E Sakoglu N Ersoy YE As A Ozdemir S 《Biological trace element research》2003,91(1):89-94
Metal ions are required as active components of several proteins, including pancreatic enzymes, and they can play important roles in the etiopathogenesis of acute pancreatitis. In the present study, we measured the concentrations of zinc (Zn) and copper (Cu) in both serum and pancreatic tissue, as markers of trace element status in an experimental acute pancreatitis model. Twenty-four male Wistar rats were divided into two groups: the experimental group (N=24) and the control group (N=10). Acute pancreatitis was induced by injection of 48% ethyl alcohol into the common biliary duct. The animals were sacrificed 24 h later to detect the concentrations of Zn and Cu. There was no significant difference in tissue Zn and Cu concentrations between control and experimental groups (p<0.05). However, in the acute pancreatitis group, serum Zn and Culevels were very significantly lower (p<0.001 and p<0.0001, respectively). In conclusuion, these findings suggested that altered mineral metabolism in serum and pancreatic tissue may have contributed to the pathophysiology of acute pancreatitis. 相似文献
13.
A corticosteroid-binding protein was detected in the whey of human colostrum and milk which resembles serum corticosteroid-binding globulin in certain respects: the equilibrium association constants for cortisol and progesterone binding and the apparent molecular size, as determined by Sephadex G-200 chromatography, were similar, and cortisol andd progesterone competed strongly for binding to the same site in each instance. Dexamethasone-binding activity could not be detected. The concentration of corticosteroid-binding protein in the colostrum obtained before parturition is about 0.1 muM; the concentration declines rapidly after parturition to about 0.01 muM. A corticosteroid-binding protein was found, also, in the whey of mature rat milk at levels of about 0.3 muM. This protein resembles rat serum corticosteroid-binding globulin: the equilibrium association constants for cortisol, corticosterone, and progesterone binding, and the apparent molecular size, as determined by Sephadex G-200 chromatography, were similar; the elution behavior of the respective proteins on anion exchange chromatography with DEAE-Sephadex A-50 was similar, also. Identity of the corticosteroid-binding proteins in whey with corticosteroid-binding globulin in serum is not presumed, however. Rat and human whey exhibited very little testosterone- or 17 beta-estradiol-binding activity. It is suggested the corticosteroid-binding proteins may play a significant physiological role in regulating the concentration of the bound and unbound forms of progesterone and cortisol in the fluids bathing the epithelial cells lining the mammary ducts and acini. 相似文献
14.
T. A. Smirnova G. Ya. Kolomiitseva A. N. Prusov B. F. Vanyushin 《Russian Journal of Plant Physiology》2006,53(4):535-540
The content of zinc and copper in coleoptiles of etiolated wheat (Triticum aestivum L.) seedlings was measured after seed germination. The content of these metals changed differently during coleoptile development and aging: the content of zinc increased substantially from the 8th to 14th day of seedling development, whereas the content of copper slightly increased on day 8 and later slightly decreased. These changes coincided with the period of increased proteolytic activity and the signs of coleoptile cell apoptotic death. Zinc accumulation and copper amount reduction in the aging coleoptile were most pronounced in the oldest apical segment of the coleoptile, which was most enriched in apoptotic cells. The modulations in the zinc and copper amounts observed might be related to the induction and continuation of terminal stages of apoptosis. 相似文献
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16.
Jun Wan Xian-wei Cui Jun Zhang Zi-yi Fu Xi-rong Guo Li-Zhou Sun Chen-bo Ji 《Biochemical and biophysical research communications》2013
The abundant proteins in human milk have been well characterized and are known to provide nutritional, protective, and developmental advantages to both term and preterm infants. Due to the difficulties associated with detection technology of the peptides, the expression of the peptides present in human milk is not known widely. In recent years, peptidome analysis has received increasing attention. In this report, the analysis of endogenous peptides in human milk was done by mass spectrometry. A method was also developed by our researchers, which can be used in the extraction of peptide from human milk. Analysis of the extracts by LC–MS/MS resulted in the detection of 1000–3000 Da peptide-like features. Out of these, 419 peptides were identified by MS/MS. The identified peptides were found to originate from 34 proteins, of which several have been reported. Analysis of the peptides’ cleavage sites showed that the peptides are cleaved with regulations. This may reflect the protease activity and distribution in human body, and also represent the biological state of the tissue and provide a fresh source for biomarker discovery. Isotope dimethyl labeling analysis was also used to test the effects of premature delivery on milk protein composition in this study. Differences in peptides expression between breast milk in term milk (38–41 weeks gestation) and preterm milk (28–32 weeks gestation) were investigated in this study. 41 Peptides in these two groups were found expressed differently. 23 Peptides were present at higher levels in preterm milk, and 18 were present at higher levels in term milk. 相似文献
17.
Metal binding has been suggested to be relevant in the antifungal and antibacterial mechanism of histatin 5, a human salivary protein. Proton nuclear magnetic resonance (NMR) spectra were obtained to investigate the specificity of metal binding to the seven histidyl, one aspartyl and one glutamyl amino acid side-chains of histatin 5 in aqueous solutions. Three C(epsilon1)-H histidyl and the C(gamma)-H glutamyl resonances of histatin 5 were selectively altered in spectra of solutions containing three equivalents of zinc. Copper binding to histatin 5 resulted in a reduced intensity of C(beta)-H aspartyl resonances, while no evidence for calcium binding was found. These results indicate that zinc binding to histatin 5 involves His-15 present within the -H-E-X-X-H- zinc binding motif, and copper binding occurs within the N-terminal D-S-H-, ATCUN motif. 相似文献
18.
Stellato F Spevacek A Proux O Minicozzi V Millhauser G Morante S 《European biophysics journal : EBJ》2011,40(11):1259-1270
In this work we present and analyse XAS measurements carried out on various portions of Prion-protein tetra-octa-repeat peptides
in complexes with Cu(II) ions, both in the presence and in the absence of Zn(II). Because of the ability of the XAS technique
to provide detailed local structural information, we are able to demonstrate that Zn acts by directly interacting with the
peptide, in this way competing with Cu for binding with histidine. This finding suggests that metal binding competition can
be important in the more general context of metal homeostasis. 相似文献
19.
The study was conducted in a hydroponics set-up to determine the suitability of zinc (Zn) and copper (Cu) contaminated wastewater as a growth medium for edible crops; to identify accumulation of Zn and Cu in different parts of the plants and to understand their effects on plant growth. Silver beet was found to produce adequate yields in the Zn (1.7 mg/L and 2.0mg/L) and Cu (0.35 mg/L and 1.1mg/L) spiked medium but not in the secondary treated domestic effluent. The plants grown in secondary treated effluent showed stunted growth and accumulated Zn and Cu to a high level in their shoots. In all other mediums Zn and Cu accumulated more in the roots. The stunted growth of silver beet in secondary treated wastewater and uptake of Zn in particular was considered to be due to the deficiency of nitrogen and other plant nutrients rather than the effect of heavy metals. The study also revealed that if there was adequate amount of macronutrients available for growth, silver beet could be grown in domestic effluent without the risk of Zn or Cu contamination to the undesired level through hydroponics. 相似文献