Selenium status,plasma zinc,copper, and magnesium in vegetarians

Plasma zinc (Zn), copper (Cu), and magnesium (Mg) concentrations, copper/zinc ratio, and selenium (Se) status were studied in 44 vegetarians (22 males and 22 females) and their age- and sex-matched nonvegetarians in the Bratislava region (Slovakia). Vegetarians had statistically significant lower levels of plasma Zn and Cu than nonvegetarians, which may be the result of lower bioavailability of Zn and Cu from this type of diet. No differences in plasma Mg levels were found between vegetarians and nonvegetarians. Se status, as expressed by plasma and erythrocyte concentrations and plasma and erythrocyte glutathione peroxidase activities (GPx), was significantly lower in vegetarians when compared to nonvegetarians. In the series as a whole, there were significantly higher correlations between plasma and erythrocyte Se concentrations and between plasma and erythrocyte GPx activities. Significant positive correlations were also found between plasma Se concentrations and erythrocyte GPx activities, and between erythrocyte Se concentrations and erythrocyte GPx activities. A vegetarian diet does not provide a sufficient supply of essential antioxidant trace elements, like Zn, Cu, and especially Se. Se supplementation should be recommended to this risk group of the population.     

Selenium and its relationship with selenoprotein P and glutathione peroxidase in children and adolescents with Hashimoto’s thyroiditis and hypothyroidism

The essential trace element selenium (Se) is required for thyroid hormone synthesis and metabolism. Selenoproteins contain selenocysteine and are responsible for biological functions of selenium. Glutathione peroxidase (GPx) is one of the major selenoproteins which protects the thyroid cells from oxidative damage. Selenoprotein P (SePP) is considered as the plasma selenium transporter to tissues. The aim of this study was to evaluate serum Se and SePP levels, and GPx activity in erythrocytes of children and adolescents with treated Hashimoto’s thyroiditis, hypothyroidism, and normal subjects.Blood samples were collected from 32 patients with Hashimoto’s thyroiditis, 20 with hypothyroidism, and 25 matched normal subjects. All the patients were under treatment with levothyroxine and at the time of analysis all of the thyroid function tests were normal. GPx enzyme activity was measured by spectrophotometry at 340 nm. Serum selenium levels were measured by high-resolution continuum source graphite furnace atomic absorption. SePP, TPOAb (anti-thyroid peroxidase antibody), and TgAb (anti-thyroglobulin antibody) were determined by ELISA kits. T₄, T₃, T₃ uptake and TSH were also measured.Neither GPx activity nor SePP levels were significantly different in patients with Hashimoto’s thyroiditis or hypothyroidism compared to normal subjects. Although GPx and SePP were both lower in patients with hypothyroidism compared to those with Hashimoto’s thyroiditis and normal subjects but the difference was not significant. Serum Se levels also did not differ significantly in patients and normal subjects. We did not find any correlation between GPx or SePP with TPOAb or TgAb but SePP was significantly correlated with Se.Results show that in patients with Hashimoto’s thyroiditis or hypothyroidism who have been under treatment with levothyroxine and have normal thyroid function tests, the GPx, SePP and Se levels are not significantly different.     

Alterations in plasma essential trace elements selenium, manganese, zinc, copper, and iron concentrations and the possible role of these elements on oxidative status in patients with childhood asthma

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r=0.485, p<0.021), and a negative correlation between TAC and MDA values (r= −0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.     

Relationship among managanese, arginase, and nitric oxide in childhood asthma

It has been demonstrated that the lowest intakes of manganese (Mn) were associated with more than a fivefold increased risk of bronchial reactivity. It was also known that nitric oxide (NO) production was found to be significantly higher in asthmatics. There is a reciprocal pathway between arginase and nitric oxide synthase (NOS) for NO production, and Mn is required for arginase activity and stability. We investigated plasma NO, arginase, and its cofactor Mn levels to evaluate this reciprocal pathway in patients with childhood asthma. Arginase activities and Mn and NO levels were measured in plasma from 31 patients with childhood asthma and 22 healthy control subjects. Plasma arginase activities and Mn concentrations were found to be significantly lower and NO levels were significantly higher found to be significantly lower and NO levels were significantly higher in patients with childhood asthma as compared to the control subjects. There was a significantly positive correlation between plasma Mn and arginase and negative correlations between arginase and NO values and Mn and NO values in patients with childhood asthma. These data indicate that the lower concentration of Mn could cause lower arginase activity and this could also upregulate NO production by increasingl-arginine content in patients with childhood asthma.     

Alterations of plasma magnesium,copper, zinc,iron and selenium concentrations and some related erythrocyte antioxidant enzyme activities in patients with Alzheimer’s disease

The aim of the present study is to evaluate the status of plasma essential trace elements magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe) and selenium (Se) concentrations and their some related antioxidant enzyme activities, erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities in patients with Alzheimer’s disease (AD). Fifty patients with AD and fifty healthy control subjects were included in this study. Plasma Cu and Zn concentrations by atomic absorption spectrometry (AAS), plasma Mg and Fe concentrations by spectrophotometric methods and plasma Se concentrations by graphite furnace AAS were determined. Erythrocyte GPx, SOD and CAT activities were measured by spectrophotometric methods. Plasma Mg, Cu, Zn, Fe and Se levels and erythrocyte GPx, SOD and CAT activities were found to be significantly lower in patients with AD compared with controls. These results suggest that alterations in essential trace elements and their related enzymes may play a role in the etiopathogenesis of AD. Also, there is a defect in the antioxidant defense system, which may lead to oxidative damage in patients with AD. The changes in antioxidant enzyme activities may be secondary to the alterations in their cofactor concentrations.     

Effect of age,sex, and race on selenium status of healthy residents of Augusta,Georgia

In this study we determined the possible effects of age, sex, and race on selenium (Se) concentration in plasma and erythrocytes and on glutathione peroxidase (GSH-Px) activity in erythrocytes. Two hundred six healthy blacks, whites, males, and females ranging in age from 11 to 60 yr were studied. For the entire population, mean±SDM Se concentrations were 0.104±0.021 μg/mL for plasma and 0.158±0.035 μg/mL for erythrocytes. Mean concentration of Se in plasma was higher in white subjects compared to black subjects (P<0.02). This difference was due exclusively to higher values in young adult white males (age, race, sex interaction). Neither plasma nor erythrocyte Se concentration nor erythrocyte GSH-Px activity were otherwise affected by age. In all groups plasma Se was correlated with erythrocyte Se (P<0.001), but not with glutathione peroxidase. Erythrocyte Se also was correlated inversely with years of smoking (P<0.033) and coffee intake (p<0.01). These results have defined the Se status in this healthy population in Augusta, Georgia as below the reported US mean. The factors underlying the age, race, sex interaction and the health significance of the low Se status in this population should be investigated.     

Optimization of selenium status by a single intraperitoneal injection of Se in Se-deficient rat: possible application to burned patient treatment

In order to investigate the efficiency of a single selenium (Se) administration in restoring selenium status, Se and antioxidant enzymes were studied in an animal model of Se depletion. In Se-depleted animals receiving or not a single parenteral administration of Se, plasma, red blood cell (RBC), and tissue Se levels were measured concurrently with glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities. The oxidative stress was assessed by thiobarbituric acid-reactive species (TBARs), total thiol groups, glutathione, and tocopherol measurements. Our study showed that Se depletion with alterations in the antioxidant defense system (Se and GPx activity decreases) led to an increase of lipid peroxidation, a decrease of the plasma vitamin E level, and SOD activation. Sodium selenite injection resulted after 24 h in an optimal plasma Se level and a reactivation of GPx activity. In liver, brain, and kidney, Se levels in injected animals were higher than those in reference animals. However, this single administration of Se failed to decrease free radical damage induced by Se depletion. Therefore, in burned patients who exhibit an altered Se status despite a daily usually restricted Se supplementation, the early administration of a consistent Se amount to improve the GPx activity should be of great interest in preventing the impairment of the antioxidant status.     

The relation between selenium, zinc and copper concentration and the trace element dependent antioxidative status.

An imbalance in the antioxidative system was connected with the development of a number of pathological processes. In order to receive values of a healthy group and to evaluate pathological changes of the trace element dependent antioxidative status in future, we investigated 99 healthy volunteers (45 male and 54 female, mean age 37.4 +/- 11.7 years). We determined the concentrations of Se, Cu and Zn, the concentrations of malondialdehyde (MDA) and the activities of the Se dependent glutathione peroxidase (GSH-Px) and the Zn/Cu dependent superoxide dismutase (SOD). The plasma concentrations (mean +/- SD) for Se, Cu and Zn were 0.84 +/- 0.10 micromol/l, 15.6 +/- 2.78 micromol/l and 12.6 +/- 1.80 micromol/l, resp., and for non protein-bound and protein bound MDA 0.27 +/- 0.07 micromol/l and 1.11 +/- 0.25 micromol/l, resp. The activity of GSH-Px in plasma and erythrocytes was 130 +/- 20.8 U/l and 19.8 +/- 4.18 U/mg Hb, resp. and of SOD in erythrocytes 3,159 +/- 847.2 U/g Hb. In plasma positive correlations have been found between Se concentrations and GSH-Px activities (p < 0.002, r = 0.31) and between GSH-Px activities and concentrations of non protein-bound MDA (p = 0.004, r = 0.28). A negative correlation has been observed between GSH-Px activities in plasma and in erythrocytes. The higher the concentrations of Cu in erythrocytes, the higher were the activities of SOD (p = 0.03, r = 0.22) and GSH-Px in erythrocytes (r = 0.26, p = 0.01), while an increasing activity of GSH-Px in these cells correlated with a decreasing concentration of non protein-bound MDA (r = -0,31, p = 0.002). An increase in BMI was connected with an increase in protein-bound MDA and a decrease in GSH-Px activities in pLasma (p = 0.002 and r = 0.23). As the results demonstrate, Se and Cu concentrations in erythrocytes can improve the trace element dependent antioxidative status.     

Selenium status of healthy immigrant parisian preschool children

Plasma selenium (Se) concentration and erythrocyte glutathione peroxidase activity (GPx) were assessed in a population of healthy preschool children two to five years old, residing in the city of Paris. In the 118 subjects, mean (±SD) plasma Se concentration was 62.10 ±13.96 μg/L, and mean GPx activity was 23.58±8.52 U/g Hb. Mean plasma Se of male children was significantly (p=0.001) higher (12%) than levels of girls. Plasma selenium levels were not correlated with erythrocyte GPx activity. Children from Mediterranean origin had a slightly lower erythrocyte GPx activity (p<0.05) than children from other regions. Mean plasma Se concentration of this group corresponded to the lower limit of intervals, which characterizes geographical regions of intermediate selenium concentrations.     

Effects of Nutritional and Excessive Levels of Selenium on Red Blood Cells of Rats Fed a High Cholesterol Diet

In this study, we investigated the effects of selenium (Se) on the properties of erythrocytes and atherogenic index in the presence and absence of high cholesterol diet (HCD). The effect of selected two different doses (1 μg and 50 μg Se/kg/body weight) on HCD-induced oxidative stress was investigated. The hemolysis of the erythrocytes of the HCD rats as well as by high levels of selenium or their combination was markedly increased. Likewise, atherogenic index and plasma glutathione peroxidase (GPx) activity were significantly increased in the same groups of rats compared to control ones. In contrast, paraoxonase activity, glutathione levels and protein thiol levels, catalase, GPx, and superoxide dismutase activities were significantly decreased in rats that received the HCD, high selenium dose, or their combination. Malondialdehyde and protein carbonyl levels in the plasma and red blood cells were significantly increased by HCD and high selenium dose administration. Co-administration of selenium at low dose with or without an HCD restored all of the investigated parameters to near-normal values. The results of this study suggest that excess selenium administration with HCD worsens the atherogenic index and enhances formation of oxidized red blood cells. At dosage levels in the nutritional range such as 1 μg Se/kg body weight, selenium ameliorates the atherogenic index and preserves the antioxidant capacity of the erythrocytes.     

Estrogen status alters tissue distribution and metabolism of selenium in female rats

A reported association between estrogen and selenium status may be important in the regulation of selenium metabolism. In this study, the effect of estrogen status on the metabolism of orally administered (75)Se-selenite and tissue selenium status was investigated. Female Sprague-Dawley rats were bilaterally ovariectomized at 7 weeks of age and implanted with either a placebo pellet (OVX) or pellet containing estradiol (OVX+E2), or were sham operated (Sham). At 12 weeks of age, 60 μCi of (75)Se as selenite was orally administered to OVX and OVX+E2 rats. Blood and organs were collected 1, 3, 6 and 24 h after dosing. Estrogen status was associated with time-dependent differences in distribution of (75)Se in plasma, red blood cell (RBC), liver, heart, kidney, spleen, brain and thymus and incorporation of (75)Se into plasma selenoprotein P (Sepp1) and glutathione peroxidase (GPx). Estrogen treatment also significantly increased selenium concentration and GPx activity in plasma, liver and brain, selenium concentration in RBC and hepatic Sepp1 and GPx1 messenger RNA. These results suggest that estrogen status affects tissue distribution of selenium by modulating Sepp1, as this protein plays a central role in selenium transport.     

Selenium and glutathione peroxidases in blood of patients with different stages of chronic renal failure

In patients with chronic renal failure (CRF) Se concentration in blood components is usually lower as compared with healthy controls. One of the five known forms of Se-dependent glutathione peroxidases (GSH-Px), the plasma GSH-Px, is synthesized primarily in the kidney. In CRF patients, plasma GSH-Px activity is reduced and the reduction increases with the progress of the disease.

The Se concentration in blood components was measured spectrofluorometrically with 2,3-diaminonaphthalene as complexing reagent. Activities of GSH-Px in red cells and in plasma were assayed by the coupled method with t-butyl hydroperoxide as substrate. The study group consisted of 150 patients in different stages of CRF. The results were compared with the values for 30 healthy subjects.

Se concentrations in whole blood and plasma of the entire group of patients were significantly lower (p < 0.01) as compared with the healthy subjects. In the incipient stage, however, the Se levels in all blood components were non-significantly lower. In whole blood and plasma the Se levels gradually decreased, reaching in the end stage values that were lower by 29 to 32% (p < 0.0001) as compared with the control group. Total protein and albumin levels in plasma of patients were significantly lower (p < 0.0001) as compared with healthy subjects and they decreased linearly with the progress of the disease. Positive and highly significant correlations were noted between total plasma protein and plasma Se concentrations (p < 0.0001) as well as between plasma albumin and plasma Se concentrations (p < 0.0001).

Red cell GSH-Px activity in the entire group of patients was lower (p < 0.05) than in the control group and did not change significantly with the progress of the disease. In plasma, however, GSH-Px activity of the entire group was lower by 33% (p < 0.0001) as compared with healthy subjects and decreased gradually with increasing renal failure. Highly significant, inverse correlations were seen between creatinine levels and plasma GSH-Px activities (p < 0.0001) as well as between urea nitrogen levels and plasma GSH-Px activities (p < 0.0001) when all stages of the disease were included.

In conclusion, patients with CRF exhibit lower Se levels in blood components as compared with healthy subjects. In whole blood and plasma these levels decrease with the progress of the disease. Plasma GSH-Px activity in patients was extremely reduced and it dramatically decreased with the progress of the illness.     

Relationship of blood trace elements to liver damage, nutritional status, and oxidative stress in chronic nonalcoholic liver disease

Trace elements are involved in chronic liver diseases because these elements may have a direct hepatic toxicity or may be decreased as a consequence of the impaired liver function, particularly in patients with alcoholic cirrhosis and/or malnutrition. In this study, we determined plasma and erythrocytes trace elements in 50 inpatients with nonalcoholic chronic liver disease (11 with biopsy-proven chronic hepatitis, 39 with cirrhosis [16 in stage A according to Child-Pugh criteria, 23 Child B+C]), and in a control group of 10 healthy subjects by the proton induced x-ray emission method. The relationship between trace element concentration and the extent of liver damage, the nutritional status (by anthropometric evaluations), and various blood markers of oxidative stress--reduced glutathione, total lipoperoxides and malonyldialdehyde--was investigated. We found that cirrhotics had a significant decrease of Fe, Zn, Se, and GSH levels in the plasma and of GSH and Se in the erythrocytes with respect to the control and chronic hepatitis groups. GSH levels were related to the degree of liver damage; a significant direct correlation was observed among Se, Zn, and GSH plasma values and between GSH and Se in the erythrocytes. The trace element decrease was, on the contrary, independent of the degree of liver function impairment and only partially affected by the nutritional status. Data indicate that liver cirrhosis, even if not alcohol related, induces a decrease of Se and Zn and that, in these patients, an oxidative stress is present, as documented by the significant correlation between Se and GSH. The plasma Br level was higher in cirrhotics with respect to the control and chronic hepatitis groups.     

High mobility group protein B1 (HMGB1) in Asthma: comparison of patients with chronic obstructive pulmonary disease and healthy controls

High mobility group protein B1 (HMGB1) has been implicated as an important mediator in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). However, the expression of HMGB1 in plasma and sputum of patients with asthma and COPD across disease severity needs to be defined. The objective of the study was to examine the induced sputum and plasma concentrations of HMGB1 in COPD and asthmatic patients to determine differences in HMGB1 levels between these diseases and their relationship with airway obstruction and inflammatory patterns. A total of 147 participants were enrolled in this study. The participants included 34 control subjects, 61 patients with persistent asthma (according to the Global Initiative for Asthma [GINA] guidelines) and 47 patients with stable COPD (stratified by Global Initiative for Chronic Obstructive Lung Disease [GOLD] status). Spirometry was performed before sputum induction. HMGB1 levels in induced sputum and plasma were determined by enzyme-linked immunosorbent assay. Sputum and plasma concentrations of HMGB1 in patients with asthma and COPD were significantly higher than concentrations in control subjects and were significantly negatively correlated with forced expiratory volume in 1 s (FEV(1)), FEV(1) (% predicted) in all 147 participants. The levels of HMGB1 in induced sputum of COPD patients were significantly higher than those of asthma patients and healthy controls (P < 0.001). This difference was present even after adjusting for sex, age, smoking status, daily dose of inhaled corticosteroids and disease severity. There were no significant differences in HMGB1 levels between patients with eosinophilic and noneosinophilic asthma. HMGB1 levels in asthmatic and COPD patients were positively correlated with neutrophil counts and percentage of neutrophils. In multivariate analysis, the two diseases (asthma and COPD) and disease severity were independent predictors of sputum HMGB1, but not smoking, age or use of inhaled corticosteroids. In conclusion, these data support a potential role for HMGB1 as a biomarker and diagnostic tool for the differential diagnosis of asthma and COPD. The importance of this observation on asthma and COPD mechanisms and outcomes should be further investigated in large prospective studies.     

Selenium supplementation on plasma glutathione peroxidase activity in patients with end-stage chronic renal failure

Patients with chronic renal failure (CRF) usually have a lower than healthy level of selenium (Se) in whole blood and plasma. Plasma glutathione peroxidase (GSH-Px) is synthesized mostly in the kidney. In CRF patients, activity of this enzyme is significantly reduced and its reduction increases with the progress of the disease. The aim of the study was to evaluate the effect of Se supplementation to CRF patients at various stages of the disease on Se concentration in blood components and on plasma GSH-Px activity. The study group comprised 53 CRF patients at various stages of the disease supplemented with Se (200 μg/d for 3 mo as Se-enriched yeast, containing about 70% l-selenomethionine [SeMet]). The control group consisted of 20 healthy subjects. The Se concentration in blood components was measured spectrofluorometrically with 2,3-diaminonaphthalene as a complexing reagent. GSH-Px activity in red cell hemolysates and plasma was assayed by the coupled method with tert-butyl hydroperoxide as a substrate. The Se concentration in whole blood and plasma of CRF patients is significantly lower as compared with healthy subjects, but similar at all stages of the disease. In the patients’ plasma, total protein and albumin levels are also significantly lower than in healthy subjects. Plasma GSH-Px activity in patients is extremely low, and contrary to Se concentration, it decreases linearly with the increasing stage of the illness. Se-supplied patients show an increased Se concentration in all blood components and at all disease stages, whereas plasma GSH-Px activity is enhanced only at the incipient stage of the disease. Se supply has no effect on plasma GSH-Px activity in uremic patients at the end stage of the disease. Total plasma protein and albumin levels did not change after Se supplementation. Our data seem to show that in patients with CRF lower total protein and albumin levels in plasma may be the chief cause of the low blood and plasma Se concentrations. GSH-Px activity decreases along with the kidney impairment. At the end stage of the disease, Se supplementation in the form of Se-enriched yeast has no effect on the increase in plasma GSH-Px activity.     

Antioxidant enzymes and lipid peroxides in children with cerebral palsy

Impaired antioxidant mechanisms are unable to inactivate free radicals that may induce a number of pathophysiological processes and result in cell injury. Thus, any abnormality in antioxidant defense systems could affect neurodevelopmental processes and could have an important role in the etiology of cerebral palsy (CP). The plasma levels of lipid peroxidation as plasma levels of malondialdehyde (MDA), activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) in plasma and erythrocytes were investigated in 34 CP children and compared with 61 normal controls. SOD, GPx and GR activities were spectrophotometrically assayed. Activities of SOD, GPx and GR in plasma did not differ significantly between CP children and the control group. Activities of erythrocyte GR in the CP patients were significantly lower compared with controls. MDA concentration did not differ statistically between the CP children and healthy subjects. In conclusion our results suggest that increased activities of erythrocyte GPx and decreased erythrocyte GR activities might be due to lesser physical activity of children with CP.     

Age-related changes in the glutathione redox system

The effect of aging on the glutathione redox system was evaluated in this study. For this purpose, we determined reduced glutathione (GSH) and oxidized glutathione (GSSG) in whole blood, glutathione peroxidase (GPx) and glutathione reductase (GSSGR) in erythrocytes and selenium (Se) in plasma in 176 healthy individuals. We also calculated GSH/GSSG molar ratios. These subjects were divided into five groups: group 1 (n=25; 0.2-1 years old); group 2 (n=28; 2-11 years old); group 3 (n=23; 12-24 years old); group 4 (n=40; 25-40 years old); group 5 (n=60; 41-69 years old). GSH levels in groups 1 and 5 were significantly lower than the other groups (p<0.001). Conversely, GSSG levels were significantly high in these periods (p<0.001). The GSH/GSSG molar ratio was found to be low both in the first year of life and in the oldest group (p<0.001, respectively). GPx activity in group 5 was increased as compared to the other groups (p<0.001). GSSGR activity was significantly lower in the oldest groups than in the other groups (p<0.001). Se levels were found to be low in the oldest group (p<0.001). Selenium levels of women in group 5 were significantly high as compared to the men (p<0.01). We found negative correlations between age and GSH levels (r=0.402; p<0.001), selenium levels (r=0.454; p<0.001), GSH/GSSG molar ratio (r=0.557; p<0.001) and GSSGR activity (r=0.556; p<0.001). There were positive correlations between age and GPx (r=0.538; p<0.001) and GSSG level (r=0.551; p<0.001). In conclusion, our findings show that the glutathione redox system is affected by age. Oxidative stress increases during the aging process. There is no effect of aging on the glutathione redox system according to sex except for the Se level.     

Effect of zinc supplementation on glutathione peroxidase activity and selenium concentration in the serum, liver and kidney of rats chronically exposed to cadmium

It was investigated whether the ability of zinc (Zn) to prevent cadmium (Cd)-induced lipid peroxidation may be connected with its impact on glutathione peroxidase (GPx) activity and selenium (Se) concentration. GPx and Se were determined in the serum, liver and kidney of the rats that received Cd (5 or 50 mg/L) or/and Zn (30 mg/L) in drinking water for 6 months in whose the protective Zn impact was noted (Rogalska J, Brzóska MM, Roszczenko A, Moniuszko-Jakoniuk J. Enhanced zinc consumption prevents cadmium-induced alterations in lipid metabolism in male rats. Chem Biol Interact 2009;177:142-52). Moreover, dependences between these parameters, and indices of lipid peroxidation (F(2)-isoprostane, lipid peroxides, oxidized low density lipoprotein cholesterol) as well as concentrations of Cd and Zn were estimated. The supplementation with Zn during the exposure to 5 mg Cd/L entirely antagonized the Cd-induced increase in GPx activity and Se concentration in the liver and kidney, but not in the serum. Zn administration during the treatment with 50 mg Cd/L totally or partially prevented from the Cd-caused decrease in GPx activity and Se concentration in the serum, liver and kidney. At the higher level of Cd exposure, GPx activity in the serum and tissues positively correlated with Se concentration. Moreover, numerous correlations were noted between GPx and/or Se and the indices of lipid peroxidation. The results indicate that the protective impact of Zn against the Cd-induced lipid peroxidation during the relatively high exposure might be connected with its beneficial influence on Se concentration and GPx activity in the serum and tissues, whereas this bioelement influence at the moderate exposure seems to be independent of GPx and Se.     

Acute Phase Response of Selenium Status and Glutathione Peroxidase Activity in Blood Plasma Before and After Total Knee Arthroplasty Surgery

Several studies show the consistent results of the decrease in plasma or serum selenium (Se) after surgery, and the change is suggested to be a negative acute phase response of Se to the surgical inflammation. Plasma glutathione peroxidase (GPx), which is included in the acute phase response proteins, is a selenoenzyme. However, previous studies failed to show any changes in GPx activity before and after surgery. In the present study, we investigated the Se- and selenoenzyme responses that accompany the acute inflammatory reactions during and following major surgery. Patients who underwent elective total knee arthroplasty surgery due to knee osteoarthritis at the Department of Orthopaedic Surgery at Gunma University Hospital in Japan were studied. The plasma Se concentration was determined, and the activity of plasma GPx was measured. C-reactive protein (CRP), albumin, blood urea nitrogen (BUN), and white blood cell (WBC) count were also analysed. Increases in the inflammatory biomarkers of CRP and WBC showed inflammatory reactions with the surgery. A significant increase in plasma GPx activity (p?相似文献   

Glutathione peroxidase activity and chemical forms of selenium in tissues of rats given selenite or selenomethionine

Glutathione peroxidase (GPx) activity and deposition of selenium (Se) were examined in tissues of rats given dietary Se for 7 wk as either selenite or selenomethionine (SeMet) with 75Se radiotracer of the same chemical form. On the basis of Se:75Se ratio, all tissues of the rats fed selenite were equilibrated with the dietary source, but tissues of the SeMet fed animals maintained a ratio of Se:75Se greater than the dietary ratio. Deposition of dietary Se and 75Se was higher in most tissues of rats fed SeMet. Muscle 75Se was the largest single tissue pool of 75Se in both groups accounting for one-third of recovered 75Se in the rats fed selenite, and one-half of recovered 75Se in the rats fed SeMet. Tissue GPx activities were not different between the two dietary groups. The proportion of Se as GPx in tissues was highest in erythrocytes of the rats fed selenite (.81) and lowest in testes and epididymides of the rats fed SeMet (.009). The proportion of Se present in cytosolic GPx was consistently higher in tissues of rats fed selenite. Erythrocytes of the rats fed SeMet had more 75Se associated with hemoglobin, and muscle cytosols of the rats fed selenite had more 75Se associated with the G-protein. The proportion of 75Se as SeMet determined by ion exchange chromatography of tissue hydrolysates was higher in tissues of rats fed SeMet (highest in muscle and hemoglobin, 70%, and lowest in testes, 16%). In contrast, selenocysteine was the predominant form of Se present in tissues of rats given selenite. These results indicate that the form of Se administered will influence the form in the tissues, the percentage of Se with GPx and the body burden of Se.