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1.
Human activities play a major role in toxic and carcinogenic metal pollution of the environment. This study was undertaken
to evaluate the effects of copper and mercury at the 400-to 1000-μM concentration range on some biochemical markers of oxidative
stress, such as lipid peroxidation (LPO), glutathione-S-transferase (GST) activity, and reduced glutathione (GSH) content
in the rainbow trout gill homogenates with or without supplementation of manganese, selenium, and bovine serum albumin (BSA).
The integrity of DNA was also measured to assess metal ion toxicity. The results showed that the LPO and specific activity
of GST were elevated. This indicated that cell-protecting antioxidant mechanisms were overtaxed and could not prevent membrane
peroxidation. Following the addition of metals, the GSH content was also significantly reduced in a concentration-dependent
manner. Mercury was found to be more effective than copper. The application of antioxidants proved beneficial in inhibiting
LPO, reducing GST activity, and elevating the GSH levels in the gill samples. Manganese was more effective than selenium and
BSA. Surprisingly, when BSA (1.0%) was added to the gill homogenates treated with a 1000-μM concentration of metal ions, instead
of alleviating malondialdehyde (MDA) generation, a drastic elevation in the MDA levels, alleviation in GST activity, and a
further decrease in glutathione (GSH) levels were observed, which were most likely the result of pro-oxidant activity of BSA.
The results also indicated that mercury and copper functioned as genotoxic pollutants, which altered the DNA integrity by
inducing the single and double-stranded DNA breaks in the gill cell nuclei. Collectively, toxicity of metal ions is related
to the depletion of GSH content and inhibition of antioxidant enzyme GST, resulting in the propagation of LPO and DNA damage. 相似文献
2.
Francisco Arnalich Angel Hernanz Dolores López-Maderuelo Mónica de la Fuente Francisco M. Arnalich Eva Andrés-Mateos 《Free radical research》2013,47(6):873-884
Diabetes mellitus may be associated with intracellular glutathione (GSH) deficiency. Since in vivo studies have shown that plasma intracellular GSH plays a key role in regulating the activation of nuclear factor κB (NF-κB), we have investigated the relationship between intracellular thiols (GSH, homocysteine, cysteine and cysteinyglycine) and NF-κB activity in the peripheral blood mononuclear cells (PBMC) of 63 elderly non-insulin dependent diabetes mellitus (NIDDM) patients (28 microalbuminurics and 35 normoalbuminurics) and 30 healthy age- and sex-matched subjects. In addition, we have measured plasma concentrations of these thiol compounds, serum concentrations of interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (sVCAM-1), that are partly dependent on the NF-κB activation, as well as the serum levels of thiobarbituric acid reacting substances (TBARS), as index of lipid peroxidation. Diabetic patients with microalbuminuria (MAB) and normoalbuminuria had NF-κB activity 2.1- and 1.5-fold greater, respectively, than the control group. As compared to normoalbuminuric patients, patients with MAB had significantly higher levels of glycemia, plasma homocysteine, and serum concentrations of TBARS, IL-6 and sVCAM-1 (in all cases, p < 0.01), and significantly lower GSH content in the PBMC (p < 0.05). The intracellular GSH in PBMC correlated with NF-κB activation (r = -0.82; p < 0.0001), serum TBARS (r = -0.60; p < 0.001), and with fasting glycemia (r = -0.56; p < 0.001) in patients with MAB, whereas a weaker association between GSH levels in PBMC and NF-κB activation (r = -0.504, p < 0.001) was seen in patients without MAB. These results suggest that the decrease of intracellular GSH content in elderly NIDDM patients with MAB is strongly associated with enhanced NF-κB activation, which could contribute to the development of increased glomerular capillary permeability and its rapid progression. 相似文献
3.
Richard P. Cosson 《Biological trace element research》1994,46(3):229-245
Determination of metal levels (Cu, Zn, Cd, Ag, Hg) in soluble and insoluble fractions of gill homogenates has been performed
after 7 d exposure of carp (Cyprinus carpio) to moderate concentrations of Cd, Ag, and Hg in water. Metallothionein levels have been quantified by polarographic method
before and after contamination and a subsequent decontamination phase (7 d). The influence of pretreatment by zinc (7 d) has
also been evaluated. Metallothionein level variations have been interpreted as having regard to interrelated flows of metal
between subcellular fractions. Special interest has been focused on heat-stable compound (HSC)-bound heavy metal flows within
the cytosol, taking in account that MT is the major component of these ligands. Our data showed differences between the ability
of metals to bind cytosolic ligands and HSCs, and their respective potency for MT induction in gill. Regardless of pretreatment,
mercury gave the highest increase of gill MT, and after the decontamination MT level remained high compared to control. Cadmium
and silver gave similar increases, but a significant difference with control appeared only after the decontamination step
with silver, whereas 1 week of contamination was enough for cadmium. Our experimental conditions gave the following order
of potency for MT induction in gill: Hg≫Cd>Ag>Zn. 相似文献
4.
Increased amounts of reactive oxygen species (ROS) are produced as a consequence of a phagocyte respiratory burst during pulmonary
inflammation. The aim of our study was to assess the concentration of malondialdehyde (MDA) and trace metals in patients with
active pulmonary tuberculosis (TB).
Eighty-three subjects were enrolled into the study and prospectively divided into three groups: 22 subjects with healthy controls
(group I), 21 patients with inactive pulmonary TB (group II), and 40 patients with active pulmonary TB (group III). Before
beginning the therapy, plasma MDA and serum concentrations of zinc (Zn), copper (Cu), albumin, and iron (Fe) were measured.
The concentration of MDA and Cu in group III were higher than in the other groups (p<0.0001). The serum Zn and albumin levels were significantly lower in group III compared with healthy controls (p<0.05). There was a positive correlation between MDA and erythrocyte sedimentation rate (r=+0.647, p<0.0001; Spearman’s test).
Our data indicated increased circulating levels of MDA and changed serum trace metal levels in active pulmonary TB. Trace
metal levels must be closely followed during the diseases process and further studies are needed to assess the role of antioxidants
as adjuvant therapy in patients with active pulmonary TB. 相似文献
5.
《Biomarkers》2013,18(8):642-648
Occupational exposure to photocopiers has been indicated as being responsible for a number of health complaints, particularly effects on the respiratory, immunological, and nervous systems. In this study, we investigated oxidative and genotoxic damage in photocopier operators by assessing catalase activity (CAT), reduced vs. oxidized glutathione ratio (GSH/GSSG), level of lipid peroxidation (TBARS), damage index by Comet assay (DICA), and buccal cells with micronuclei (BCMN). Our results reveal that the TBARS levels in operators were increased (27%; p<0.05) but that no significant alterations to GSH/GSSG or CAT activity were observed. The DICA and the number of BCMN were significantly increased (134% and 100%, respectively; p<0.05) in the exposed group. There was a significant association between the time in months spent at work and DNA damage in lymphocytes (rs?=?0.720; p<0.001) and buccal cell with MN (rs?=?0.538; p<0.001). Because laser printers and photocopiers have become increasingly used, it is important to control human exposure using reliable biomarkers. 相似文献
6.
Fluorescence spectroscopy in combination with UV–Vis absorption spectroscopy were employed to investigate the binding of an
antibacterial drug Ciprofloxacin (CPFX) to bovine serum albumin (BSA) under the physiological conditions. In the discussion
of the quenching mechanism, it was proved that the fluorescence quenching of BSA by CPFX is a result of the formation of CPFX-BSA
complex. Binding parameters were determined using the modified Stern-Volmer equation and Scatchard equation to provide a measure
of the binding affinity between CPFX and BSA. The results of thermodynamic parameters ΔG, ΔH, ΔS, at different temperatures indicate that the electrostatic interactions play a major role for CPFX-BSA association. Site
marker competitive experiments indicated that the binding of CPFX to BSA primarily took place in site I. Furthermore, the
effect of metal ions to CPFX-BSA system was studied, and the distance r between donor (BSA) and acceptor (CPFX) was obtained according to fluorescence resonance energy transfer (FRET). The conformation
of BSA upon CPFX binding was evaluated by measuring synchronous fluorescence properties of the CPFX-BSA complex. 相似文献
7.
Samiran Bisai Dilip Mahalanabis Kaushik Bose 《International Journal of Anthropology》2006,21(3-4):241-246
This study compared several maternal risk factors of low birth weight (LBW) between 204 normal birth weight (NBW) and 133
LBW newborns from Kolkata, India. Based on their birth weight (BW), newborns were classified as LBW (BW < 2.5 kg) and NBW
(BW ≥ 2.5 kg). Results revealed that means for maternal age (MA, p < 0.05), gestational age (GA, p < 0.01), hemoglobin (Hb) concentration (p < 0.05), and per capita daily income (PCDI, p < 0.05) were significantly higher among mothers of NBW. Correlation analyses revealed that MA (r = 0.119, p < 0.05), GA (r = 0.583, p < 0.01), PCDI (r = 0.118, p < 0.05), and Hb (r = 0.138, p < 0.05) were significantly positively correlated with BW; PCDI was also significantly positively correlated (r = 0.142, p < 0.01) with Hb. Stepwise regression analyses with BW as the dependent variable revealed that GA (t = 7.915, p < 0.001) and Hb (t = 2.057, p < 0.05) were the most important predictive variables. The effect of Hb, independent of GA, was statistically significant
(change in F = 4.231, p < 0.05). Because GA is not modifiable in pregnant women, there is a need to increase Hb levels among pregnant mothers. Most
importantly, appropriately targeted preventive strategies, including iron supplementation, need to be implemented for health
promotion. 相似文献
8.
The concentrations of cadmium, lead, selenium, and zinc in blood and seminal plasma were determined in 76 Singapore males.
Except for zinc, the concentrations were generally higher in blood than in seminal plasma (cadmium, 1.31 μg/L vs 0.61 μg/L;
lead, 82.6 μg/L vs 12.4 μg/L, and selenium, 163.6 μg/L vs 71.5 μg/L). The mean concentration of zinc in seminal plasma was
more than 30 times higher than in blood (202 mg/L vs 6.2 mg/L). Significant positive correlations were found between the concentrations
in blood and seminal plasma for the two essential trace elements: selenium (r=0.45,p<0.001) and zinc (r=0.25,p<0.05). However, no relationships were found between the concentrations in blood and seminal plasma for two toxic metals (cadmium
and lead). Significant inverse correlations were observed between Cd and Zn (r=−0.40,p<0.01), and Pb and Se (r=−0.32,p<0.05) in blood, whereas significant positive correlations were noted between Cd and Se (r=0.45,p<0.01), Cd and Zn (r=0.35,p<0.05), and Se and Zn (r=0.57,p<0.001) in seminal plasma. The physiological significance of these relationships are also discussed in this paper. 相似文献
9.
M. G. Sá G. A. Ahearn F. P. Zanotto 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2009,179(5):605-615
Gills are the first site of impact by metal ions in contaminated waters. Work on whole gill cells and metal uptake has not
been reported before in crustaceans. In this study, gill filaments of the American lobster, Homarus americanus, were dissociated in physiological saline and separated into several cell types on a 30, 40, 50, and 80% sucrose gradient.
Cells from each sucrose solution were separately resuspended in physiological saline and incubated in 65Zn2+ in order to assess the nature of metal uptake by each cell type. Characteristics of zinc accumulation by each kind of cell
were investigated in the presence and absence of 10 mM calcium, variable NaCl concentrations and pH values, and 100 μM verapamil,
nifedipine, and the calcium ionophore A23187. 65Zn2+ influxes were hyperbolic functions of zinc concentration (1–1,000 μM) and followed Michaelis–Menten kinetics. Calcium reduced
both apparent zinc binding affinity (K
m) and maximal transport velocity (J
max) for 30% sucrose cells, but doubled the apparent maximal transport velocity for 80% sucrose cells. Results suggest that calcium,
sodium, and protons enter gill epithelial cells by an endogenous broad-specificity cation channel and trans-stimulate metal
uptake by a plasma membrane carrier system. Differences in zinc transport observed between gill epithelial cell types appear
related to apparent affinity differences of the transporters in each kind of cell. Low affinity cells from 30% sucrose were
inhibited by calcium, while high affinity cells from 80% sucrose were stimulated. 65Zn2+ transport was also studied by isolated, intact, gill filament tips. These intact gill fragments generally displayed the same
transport properties as did cells from 80% sucrose and provided support for metal uptake processes being an apical phenomenon.
A working model for zinc transport by lobster gill cells is presented. 相似文献
10.
Olusi S Al-Awadhi A Abiaka C Abraham M George S 《Biological trace element research》2003,91(2):137-144
Leptin, the obesity gene protein product, is a hormone with multiple physiological functions in the human. However, there
are few reports in the literature on its role in trace element metabolism in the normal population. Therefore, we investigated
the association among serum leptin, zinc, copper, and zinc/copper ratio in 570 healthy men and women aged 15 yr and older.
Serum leptin assay was done with a commercial enzymelinked immunosorbent assay kit; serum zinc and copper levels were measured
by an atomic absorption spectrophotometer. Serum leptin was found to be positively associated with age (r=0.254, p<0.001), sex (r=0.406, p<0.001), body mass index (BMI) (r=0.553, p<0.001), and serum copper (r=0.419, p<0.001), but negatively associated with the zinc/copper ratio (r=−0.423, p<0.001). There was no significant association between serum leptin and zinc (r=−0.131, p>0.05). When the confounding effects of age, sex, and BMI were removed, serum leptin was still positively associated with
serum copper (r=0.197, p=0.02) and the serum zinc/copper ratio (r=−0.182, p=0.03). These results suggest that copper and not zinc has an effect on serum leptin levels. 相似文献
11.
As an essential nutrient involved in carbohydrate and lipid metabolism, chromium is of extraordinary importance for patients
with diabetes. Plasma concentrations do not reflect the chromium supply; thus, we determined the element’s content in blood
cells in order to evaluate the body status. We investigated 86 blood donors (C) and 35 diabetics type 2 (Dm2). After the isolation
of the blood cells by using a density centrifugation, the chromium concentrations were determined by electrothermal atomic
absorption spectrometry. Compared to C, Dm2 had higher values in plasma, erythrocytes, and platelets (248%, 61%, and 91%,
respectively) and lower contents in polymorphonuclear and mononuclear leukocytes (each −35%, age- and sex-matched groups with
n=35, each p<0.01). The poorer the metabolic control assessed by HbA1c, the higher were the chromium concentrations in plasma (r=+0.46, n=33, p=0.007, increase 11.1% per %HbA1c) and the lower were the values in mononuclear leukocytes (r=−0.45, n=33, p=0.008, decrease 17.8% per %HbA1c). The changed amounts in plasma and in mononuclear cells in increasing hyperglycemia could
be the result of an intracellular/extracellular redistribution of the element. High plasma levels might explain the renal
chromium losses of diabetics, whereas the lymphocytes could reflect a decreasing chromium body state. 相似文献
12.
The objective was to determine the prevalence of iodine deficiency among hypothyroid patients and the effect of dietary goitrogens
on indices of iodine and thyroid status. This is a case-control study of 106 subjects who were recruited from King Abdulaziz
University Hospital, Jeddah. Blood and urine were collected for serum thyroid hormones, thyroid autoantibodies, thyroglobulin
(Tg) and urinary iodine concentration (UIC). Dietary iodine and goitrogenic food intake were assessed by questionnaire. Using
World Health Organization (WHO) cutoff values for UIC, both controls and cases were iodine deficient (85% and 83%, respectively).
Furthermore, dietary iodine was deficient in 23% of controls and 36% of cases. In cases, there was a positive association
between UIC levels and serum thyroid stimulating hormone (r = 0.405, p < 0.01) and a negative association with serum fT4 (r = −0.358, p < 0.01). Serum Tg antibody titers were also positively associated with dietary iodine (r = 0.328, p < 0.05). Patients with elevated serum autoantibodies had lower UIC and dietary iodine than those with normal serum autoantibodies.
UIC was associated with dietary goitrogens including turnip (r = 0.280, p < 0.05) and pine (r = 0.289, p < 0.05) among cases. Iodine deficiency is common and the consumption of dietary goitrogens is high among euthyroid and hypothyroid
subjects living in Jeddah. 相似文献
13.
Małgorzata Krasińska Zygmunt Gżejewski Elżbieta Czykier Zbigniew A. Krasiński Magdalena Matuszewska 《Acta theriologica》2009,54(2):111-126
The material for this study was obtained from culled European bison (Linnaeus, 1758) originating from both captive breeding
and free-ranging populations in Białowieża and Borecka Forests (north-east Poland), and was mostly collected from November
until April. Mass difference between the right and left testis of the same individual up to 30% was considered to be physiological
asymmetry, which proved typical of the species. Hypoplasia or atrophy of the testes exceeding 30% in size, were found in 37
males (13.6% of the examined animals;n=272). Cryptorchidism was recorded in 20 bison culled in Białowieża Forest at the age over 1 year (10.6% of individuals at
the same age;n=188). We registered the weight of testes of 259 males aged 2 months to 20 years. In the examined males, no distinct predominance
in size and weight between the right and left testes was observed. The weight of testes was significantly correlated with
age (r=0.85,p < 0.0001) and body weight (r=0.93,p < 0.0001). The heaviest testicles belonged to older and sexually mature bulls aged 6–12 years (mean 216 g) and to old ones
over 13 years (mean 242 g). Two testis measurements (length and width) were taken from 136 culled males, while two additional
measurements (total length with the cauda of epididymis and circumference) from 65 males. The length and width of the testes
were moderately correlated with age (r=0.31 andr=0.20,p < 0.01) and highly significantly correlated with testis (r=0.79,p < 0.001) and body weight (r=0.92,p < 0.001). 相似文献
14.
Markus P. Look Jürgen K. Rockstroh Govind S. Rao Karl A. Kreuzer Ulrich Spengler Tilman Sauerbruch 《Biological trace element research》1997,56(1):31-41
Serum selenium levels were determined cross-sectionally in 57 HIV-infected patients who were classified according to the Centers
for Disease Control (CDC) 1993 classification system. Mean serum selenium levels were lower in CDC stage II (58.7±12.2 μg/L;p<0.01;n=18) and stage III (47.6±11.3 μg/L;p<0.01;n=19) HIV-infected patients, than in healthy subjects (80.6±9.6 μg/L;n=48) and stage I patients (73.6±16.5 μg/L;n=20). Serum selenium levels were positively correlated with CD4 count, CD4/8 ratio, hematocrit, and serum albumin (r=0.42;r=0.39;r=0.48; andr=0.45;p<0.01, respectively) and inversely with serum levels of thymidine kinase (r=−0.49;p<0.01;n=49) and β2-microglobulin (r=−0.46;p<0.001;n=49). In addition, serum selenium levels in 20 randomly selected AIDS-free individuals (CDC I:n=10; CDC II:n=10) were inversely correlated with serum concentrations of interleukin-8 (IL-8) and soluble tumor necrosis factor receptors
(sTNFR) types I and II. There was no correlation with serum immuneglobulin A and total serum protein levels. The results show
that the progressive deprivation of serum selenium in HIV-infection is associated with loss of CD4+-cells and with increased levels of markers of disease progression and inflammatory response. 相似文献
15.
Twenty-seven infants with classical phenylketonuria were evaluated longitudinally for 6 mo while ingesting PhenexTM -1 Amino Acid Modified Medical Food With Iron as their primary protein source. Intake of selected nutrients and biochemical
indices of trace and ultratrace mineral status and plasma retinol and α-tocopherol concentrations were evaluated. The means
of iron status indices (complete blood count, plasma ferritin, iron, transferrin saturation, total iron binding capacity)
and the plasma concentrations of trace and ultratrace minerals (copper, manganese, molybdenum, selenium, zinc) and plasma
retinol and α-tocopherol were in the reference ranges. Vitamin A intakes (r = 0.49,p < 0.05) and plasma retinol-binding protein concentrations (r = 0.42,p < 0.05) were positively correlated with plasma retinol concentrations at 3 mo of study. At 6 mo, concentrations of plasma
transthyretin (r = 0.72,p < 0.01) and retinolbinding protein (r = 0.48,p < 0.05) were positively correlated with plasma retinol concentrations. At 6 mo, concentrations of plasma transthyretin (r = 0.52,p < 0.05) were positively correlated with retinol-binding protein concentrations. Phenex-1 supports normal mean iron status
indices and mean concentrations of trace and ultratrace minerals, retinol, and α-tocopherol when fed in adequate amounts. 相似文献
16.
YongXia Wang XiuAn Zhan XiWen Zhang RuJuan Wu Dong Yuan 《Biological trace element research》2011,143(1):261-273
This study was conducted to investigate the effects of different sources of dietary selenium (Se) supplementation on growth
performance, meat quality, Se deposition, and antioxidant property in broilers. A total of 600 one-day-old Ross 308 broilers
with an average body weight (BW) of 44.30 ± 0.49 g were randomly allotted to three treatments, each of which included five
replicates of 40 birds. These three groups received the same basal diet containing 0.04 mg Se/kg, supplemented with 0.15 mg
Se/kg from sodium selenite (SS) or from l-selenomethionine (l-Se-methionine (Met)) or from d-selenomethionine (d-Se-Met). The experiment lasted 42 days. Both Se source and time significantly influenced (p < 0.01) drip loss of breast muscle. Supplementation with l-Se-Met and d-Se-Met were more effective (p < 0.05) in decreasing drip loss than SS. Besides, the pH value of breast muscle was also significantly influenced (p < 0.05) by time. The SS-supplemented diet increased more (p < 0.05) liver, kidney, and pancreas glutathione peroxidase (GSH-Px) activities than the d-Se-Met-supplemented diet. In addition, l-Se-Met increased more (p < 0.01) liver and pancreas GSH-Px activities than d-Se-Met. The antioxidant status was greatly improved in broilers of l-Se-Met-treated group in comparison with the SS-treated group and was illuminated by the increased glutathione (GSH) concentration
in serum, liver, and breast muscle (p < 0.05); superoxide dismutase (SOD) activity in liver (p < 0.01); total antioxidant capability (T-AOC) in kidney, pancreas, and breast muscle (p < 0.05) and decreased malondialdehyde (MDA) concentration in kidney and breast muscle (p < 0.05) of broilers. Besides, supplementation with d-Se-Met was more effective (p < 0.01) in increasing serum GSH concentration and decreasing breast muscle MDA concentration than SS. l-Selenomethionine supplementation significantly increased GSH concentration in liver and breast muscle (p < 0.05); SOD activity in liver (p < 0.01); and T-AOC in liver, pancreas, and breast muscle (p < 0.05) of broilers, compared with broilers fed d-Se-Met diet. The addition of l-Se-Met and d-Se-Met increased (p < 0.01) Se concentration in serum and different organs studied of broilers in comparision with broilers fed SS diet. Therefore,
dietary l-Se-Met and d-Se-Met supplementation could improve antioxidant capability and Se deposition in serum and tissues and reduce drip loss of
breast muscle in broilers compared with SS. Besides, l-Se-Met is more effective than d-Se-Met in improving antioxidant status in broilers. 相似文献
17.
The aim of the present study is to evaluate the status of plasma essential trace elements selenium (Se), zinc (Zn), copper
(Cu), and iron (Fe) concentrations and their related acute-phase proteins, ceruloplasmin (Cp), ferritin, transferrin (Tf),
and albumin levels in patients with vivax malaria. Plasma Cu and Zn concentrations were determined by atomic absorption spectrometry
(AAS). Se concentrations were determined by graphite furnace AAS. Fe, Cp, Tf, and albumin levels were determined by colorimetric
methods. Plasma Se, Fe, and albumin levels were found to be significantly lower (p<0.01, p<0.001, and p<0.05, respectively) and Cu, Cp, and ferritin levels and Cu/Zn ratios were significantly higher (p<0.001, p<0.001, p<0.001, and p<0.05, respectively) in patients when compared with those of healthy subjects. Plasma, Tf, and Zn levels were not found to
be significantly different (p>0.05) in patients and controls. There were positive important correlations between Cu and Cp (r=0.908, p<0.001), Zn and albumin (r=0.633, p<0.001), and negative correlations between Fe and ferritin content (r=−0.521, p<0.05) and Fe and Tf (r=−0.616, p<0.01) in the patients group. Our findings demonstrated that plasma essential trace elements Se, Cu, and Fe change, but these
changes might be dependent on acute-phase proteins, which were regulated as a part of defense strategies of the organism,
induced by hormonelike substances. 相似文献
18.
Paula N. Morgan Francoise Costa Carmen M. Donangelo Janet C. King 《Biological trace element research》1994,42(2):129-142
The aim of this study was to determine whether the postprandial decline in plasma zinc concentration is altered by aging.
Eleven women, between the ages of 65 and 82 yr, participated in two separate experimental protocols: a high carbohydrate breakfast
trial and a fasting trial. Plasma zinc concentrations were measured from blood samples obtained at 8∶00am (baseline fasting) and at 30-min intervals until 1∶00pm during each trial. Following the breakfast meal, plasma zinc concentrations declined 14% from 75±1 to 65±2 μg/dL (p<0.05), reaching a nadir 2.7±0.2 h after the meal. This decline was significantly (p<0.0001) greater than the 3.6% fall observed during the fasting trial. Postprandial changes in the plasma zinc concentrations
were correlated with postprandial changes in serum glucose (r=−0.43,p<0.001), serum insulin (r=−0.17,p<0.01), and serum phosphorus(r=0.32,p<0.005). These data show that plasma zinc concentrations decline following food intake in elderly women in the same manner
as previously described for younger adult women. 相似文献
19.
Reza Amani Somaye Saeidi Zahra Nazari Sorour Nematpour 《Biological trace element research》2010,137(2):150-158
It has been suggested that mood disorders and depressive status may be accompanied by lowered zinc status in the body, and
adequate consumption of zinc increases a general perceived well-being. The main objective of this study was to assess the
correlation between serum zinc concentrations and dietary zinc intakes with depression scores in university female students.
In the first phase, Beck's depression questionnaire was applied in a random sampling of 308 selected 20–25-year-old female
students (one third of total students in Ahvaz Jondi-Shapour University of Medical Sciences Golestan dormitories) to assess
the major depressive disorder (MDD) scales. Then, in the second phase, 23 students who identified as having moderate and severe
depression were selected as the case group, and 23 healthy age matched were chosen as the controls. Each of them completed
a 12-item semiquantitative food frequency questionnaire containing the main food sources of zinc in the usual dietary patterns
and also a 24-h food recall questionnaire to assure the daily zinc intakes. Daily zinc intakes were obtained by multiplying
each portion size by its zinc content using food tables. A 5-ml blood sample was taken for further serum zinc status using
flame atomic absorption spectrophotometry technique. Pearson's r was used to show the correlation between quantitative variables. Both daily zinc intake and serum zinc concentrations of
MDD group were about two thirds of healthy index (p < 0.01). Depressed individuals used to eat lower servings of red meats and chicken as the main food sources of zinc in students'
usual diets (p < 0.001). Consumption of other foods as the sources of zinc was not significantly different in two groups. A linear significant
correlation between dietary zinc intakes and its serum levels was seen in samples (r = 0.62; p < 0.001) and MDD students (r = 0.55; p < 0.001). There was a linear inverse correlation between Beck questionnaire scores and serum zinc concentrations in all of
the investigated students(r = -0.65; p < 0.001) and MDD girls (r = −0.71; p < 0.001). Beck questionnaire scores and diatary zinc intakes were also inversly correlated (r = −0.58; p < 0.001). However, no statistical correlation was seen between these two variables in MDD cases. In depressed female students,
dietary zinc intake is correlated to its serum concentrations; however, the serum zinc levels are inversely correlated to
depression scales. Consumption of the main dietary sources of zinc such as red meats and chicken should be encouraged in young
depressed girls. 相似文献
20.
It is well known that antioxidants containing sulfhydryl (−SH) groups are protective against the toxic effects of mercury.
The current study was designed to elucidate the mechanism(s) of the cytoprotective effects of glutathione (GSH) and N-acetylcysteine (NAC) against the toxicity of inorganic mercury (HgCl2) in neuroblastoma cells (N-2A). The obtained results demonstrated the protective effects of these compounds in a dose dependant
manner up to 95 and 74% cell viability, respectively as compared to the control of HgCl2 of 10%. The administration of buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, increased the toxicity of HgCl2 in a dose dependent manner. Moreover, BSO treatment attenuated the levels of the cellular free −SH concentrations at low
concentrations (1–100 μM) of HgCl2. The data also show that cellular thiol concentrations were augmented in the presence of GSH and NAC and these compounds
were cytoprotective against HgCl2 and this is due to up regulating of GSH synthesis. A reduction in intracellular levels of GSH was observed with treatment
of HgCl2. In addition, the ratio of GSH/GSSG increased from 16:1 to 50:1 from 1 to 10 μM concentration of HgCl2. The ratio of GSH/GSSG then decreased from 4:1 to 0.5:1 with the increase of concentration of HgCl2 between 100 μM and 1 mM due to the collapse of the N-2A cells. It was of interest to note that the synthesis of GSH was stimulated
in cells exposed to low concentration of HgCl2 when extra GSH is available. These data support the idea that the loss of GSH plays a contributing role to the toxic effects
of HgCl2 and that inorganic mercury adversely affects viability, through altering intracellular −SH concentrations. The data further
indicate that the availability of GSH to the cells may not be sufficient to provide protection against mercury toxicity and
the de novo synthesis of intracellular GSH is required to prevent the damaging effects of mercury. 相似文献