Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities, serum trace elements (Se, Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20-60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.     

Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities,serum trace elements (Se,Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada,Island of San Miguel,The Azores Archipelago,Portugal

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20–60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.     

Effects of halothane, enflurane, and isoflurane on plasma and erythrocyte antioxidant enzymes and trace elements

Alterations of the normal redox balance in mammals might be attributed to increases of plasma free-radical concentrations and/or a disruption of the protective mechanisms. These conditions lead to damage to cellular structure by the mechanism of lipoperoxidation, particularly in the liver, kidney, and central nervous system. In this study, the effect of general anesthesia on the oxidative metabolism of human plasma and erythrocytes was investigated. Forty-five patients undergoing anesthesia by using halothane, enflurane, or isoflurane were included in this study. Blood samples were taken preoperatively, the first hour, the first day, and the third day after the operation. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities and trace elements such as cofactor copper (Cu), zinc (Zn) and selenium (Se) levels were measured in plasma and red blood cells. Our results showed that halothane and enflurane administration increased the plasma GSH-Px activity and reduced zinc levels. In addition, they lowered SOD and GSH-Px activities and trace element levels on erythrocytes. Isoflurane had no effect on plasma antioxidant enzymes, but, similar to the other, isoflurane decreased the plasma zinc levels, erythrocyte SOD and GSH-Px activities and trace element levels. Gülhane Military Medical Academy     

Trace element status (Se, Cu, Zn) in healthy portuguese subjects of Lisbon population

Serum levels of selenium, copper, and zinc were systematically determined in healthy subjects of the Lisbon population. The sample consisted of 183 blood donors of both genders who were divided into two age groups: 20–44 and 45–70 yr of age; relationships with gender, age, the lipid profile, and tobacco consumption were investigated. In the female group, the intake of oral contraceptives and pregnancy were considered for the youngest women, and hormonal replacement therapy (HRT) was taken into account for the oldest ones. Serum concentrations of these elements were in the same range as those found for populations of other European countries. Differences between genders were observed for the three elements studied, with serum selenium and zinc concentrations higher in men and copper levels higher in women. Age-dependent differences were found for selenium: The oldest subjects (regardless gender) presented the highest concentrations of selenium in serum as further demonstrated by the positive correlation with age. In both pregnant and contraceptive-using women, copper was greatly increased, confirming the influence of estrogen status and/or oral contraceptive intake on increased serum copper levels. However, in postmenopausal women, HRT did not significantly affect serum copper levels. Selenium, copper, and zinc status were not different between normolipidemic and hyperlipidemic subjects for the same gender and age range, but selenium levels tended to increase with hyperlipidemia when considering the whole group of subjects. With respect to the lifestyle, higher serum zinc levels were found in tobacco-consuming men. Albumin serum levels were similar for all considered subgroups, except for the pregnant women, for whom a decrease in this parameter was observed. The present study allowed one to obtain reference values for this healthy group of population, which will serve for a comparative study with groups having pathological conditions, such as cardiovascular disease.     

Plasma Copper, Zinc, and Selenium Levels and Correlates with Metabolic Syndrome Components of Lebanese Adults

Zinc, copper, and selenium statuses were reported to be linked to the development of chronic diseases, especially coronary heart disease (CHD). Metabolic syndrome, a known CHD risk factor, was found to be highly prevalent in Lebanon. Nevertheless, no data are available on the statuses of plasma zinc, copper, and selenium, especially in terms of their relation to the components of the metabolic syndrome. A sample of 398 men and women aged 18-65 years was drawn from 23 health centers across Lebanon; anthropometric measurements and biochemical analyses of fasting plasma samples were performed. Subjects were found to have normal plasma statuses of copper and selenium but were at elevated risk of zinc deficiency. Plasma selenium levels correlated positively with all the components of the metabolic syndromes, while that of copper correlated only with total, high-density lipoprotein and low-density lipoprotein cholesterol. Plasma zinc did not correlate with any of the metabolic syndrome components.     

Evaluation of selenium supply and status of inhabitants in three selected rural and urban regions of the Czech Republic

Blood serum selenium of 65 men and hair selenium of 77 men from three regions of the Czech Republic (CR) were analyzed by neutron activation analysis, and 202 samples of urine from the same populations were analyzed for Se by the fluorimetric method to assess selenium status of these regions. Low status (53 μg Se/L of serum and 0.29 μg Se/g lyophilized hair as means) and very low urine selenium (8.7 μg/L urine) were detected. By these data, the CR is among the countries with the lowest Se intake. A comparison of studied regions is presented. Moreover, values of serum zinc were within the reference range, but mild to moderate deficiency in the supply of iodine was detected.     

Do Zinc and Selenium Prevent the Antioxidant, Hepatic and Renal System Impairment Caused by Aspirin in Rats?

Aspirin is widely used as an antiinflammatory drug especially in children with rheumatic fever arthritis. The diminishing effects of aspirin on antioxidant enzymes and hepato-renal systems at high doses are well-known. It is now evident that the damage at antioxidant system worsens the clinical picture of the disease and prolongs the treatment time. Thus, we investigated the effect of antioxidant enzyme cofactors-zinc and selenium-supplementation on superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels (erythrocyte and liver) and hepato-renal toxicity during aspirin treatment at therapeutic doses. The rats were divided into five groups. The first and second groups were given aspirin 75 mg/kg/day and aspirin plus selenium (Selenium 200, selenium 200 mg tablet as selenium yeast, GNC) and zinc (Zinc 100, zinc 100 mg tablet as zinc gluconate, GNC), respectively, the third and fourth take 50 mg/kg/day aspirin and aspirin plus selenium and zinc twice a day, respectively. The fifth group was control. The rats were treated with aspirin for 5 weeks as in the treatment of rheumatic fever arthritis in children. Erythrocyte SOD and MDA levels were preserved with supplementation, whereas there was no change for GSH-Px levels. Liver SOD, GSH-Px, and MDA levels were not changed. In zinc- and selenium-supplemented groups, the levels of serum alanine aminotransferase, uric acid, and direct bilirubin levels were found statistically decreased compared with nonsupplemented groups. There was no significant histopathologic change in specimens of hepatic and renal tissues. Trace element supplementation may prevent free radical damage and shorten treatment time in children using long-term aspirin treatment.     

Rapid and direct determination of selenium, copper, and zinc in blood plasma by flow injection-inductively coupled plasma-mass spectrometry

A flow injection-inductively coupled plasma-mass spectrometry (FI-ICP-MS) with a simple sample preparation procedure was developed for the determination of selenium, copper, and zinc in blood serum/plasma. A serum/plasma sample was filtered through a 0.45-μm membrane filter and diluted with a mixture of trace elements in a standard solution (9∶1, v/v). Measurement of the reference serum sample confirmed the accuracy of our method for selenium, copper, and zinc concentration. In the case of blood plasma samples obtained from six healthy adult males, the selenium, copper, and zinc concentrations were similar to those of a typical healthy male in Japan. These results suggest that the sample prepartive procedure coupled with FI-ICP-MS can be used for the routine determination of selenium, copper, and zinc in human blood serum/plasma.     

Idiopathic scoliosis and concentrations of zinc,copper, and selenium in blood plasma

The concentration of zinc, copper, selenium, albumin, and ceruloplasmin in blood plasma and the activity of superoxide dismutase and glutathione peroxidase in erythrocytes were determined in a set of patients with idiopathic scoliosis (n=51). A significant decrease of selenium concentration (0.50±0.16 μmol/L) was found when compared with a control group (0.69±0.07 μmol/L) (p<0.01). The same levels of significance were found out for selenium levels corrected for albumin content. In a group of patients with a curvature over 45° indicated for a surgical correction, the average plasma concentrations of selenium were significantly lower (p<0.05) in comparison with a group of patients with a curvature below 45° treated conservatively. The GSH-Px activity in erythrocytes was the same in both sets. In comparison with the controls, no significant differences were revealed in all of the other parameters. The detection of the decreased blood plasma concentration of selenium has suggested possible disturbance of well-proportioned distribution and of general optimal availability of selenium in the organism of patients with idiopathic scoliosis with likely effects on the process of synthesis and maturation of collagen affecting the axial skeleton stability.     

Alterations of serum selenium, zinc, copper, and iron concentrations and some related antioxidant enzyme activities in patients with cutaneous leishmaniasis

The aim of this study was to measure the alterations in serum selenium (Se), copper (Cu), zinc (Zn), and iron (Fe) concentrations and their carrier proteins, ceruloplasmin (Cp), transferrin (Tf) albumin, and related antioxidant enzyme activities, erythrocyte Cu-Zn Superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities in patients with cutaneous leishmaniasis (CL). Erythrocyte Cu-Zn SOD activities, serum Cu concentrations, and Cp levels were found to be significantly higher in the patients group than those of controls. However, GSH-Px and CAT activities and Se, Zn, Fe, and Tf levels were lower in patients than in the control subjects. There were positive important correlation’s between Cu-Zn SOD and Cp, Cu-Zn SOD and Cu, Cp and Cu, GSH-Px and Se, and Fe and CAT in the patients group. Our results showed that serum essential trace elements Se, Zn, Cu, and Fe concentrations and their related enzymes Cu-Zn SOD, GSH-Px, and CAT activities change in CL patients. The changes may be a part of defense strategies of organism and are induced by the hormonelike substances.     

Plasma values of oxidants and antioxidants in acute brain hemorrhage

The levels of oxidants xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA) and of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione reductase (GRD) were determined in plasma within 24 h after onset of hemorrhagic stroke in 17 patients (9 men and 8 women, aged 60.7+/-11.5 yr) and in 20 healthy controls (12 men and 8 women, aged 62.5+/-8.3 yr). Compared to controls, the plasma SOD and total superoxide scavenger activities (TSSA) were significantly lower and the NO levels were significantly higher among the stroke patients. XO showed a slight, nonsignificant increase in the patients, but the levels of MDA, NSSA, GRD, and GSH-Px did not show any significant differences between the two groups. The hemorrhage volume was negatively correlated with the initial score of the Glasgow Coma Scale and a positive correlation with lethal outcome, but it did not correlate significantly with any of the measured parameters. The results suggest that free radicals might play a role in the development of brain injury following brain hemorrhage.     

Influence of selenium and zinc on performance,blood constituents,and immune response in stressed calves

Eighty weanling beef calves were used to determine the effects of zinc and selenium supplementation on performance, immune response, and blood characteristics during stress. Treatments included: (1) control; (2) control diet with selenium injection [15 mg/hd (head)] (3) zinc diet (25 mg Zn/hd/d, added as ZnO); and (4) zinc diet with selenium injection. Feed intake and weight gains were not affected by zinc throughout the 28-d study. However, selenium improved weight gains in calves with low initial selenium status in the first 14 d of the study. Glutathione peroxidase (GSH-Px) was increased by selenium and decreased by zinc on d 19. Zinc appeared to interfere with the role of selenium in GSH-Px activity at the cellular level. Plasma zinc was not affected by treatment. Zinc supplementation resulted in increased serum sodium and decreased serum total protein and glutamic-oxaloacetic transaminase. Immune response was measured via antibody titers to Infectious Bovine Rhinotracheitis (IBR) and Para-influenza₃ (PI₃) viruses 19 d postvaccination. Levels of titers were not affected by either zinc or selenium, however, titers did reflect a response to vaccination between sampling dates. On d 19, zinc increased the percentage of leukocytes that were monocytes. Total leukocyte, neutrophil and lymphocyte numbers did not differ across treatments. These results suggest that selenium or zinc supplementation may individually improve an animal’s response to stress.     

Antioxidative metabolism in down syndrome

Down syndrome is the most common cause of mental retardation, affecting 1 in 700–800 liveborn infants. Although numerous biochemical abnormalities accompanying the syndrome have not yet been completely clarified, the antioxidant defense system enzymes have shown to be altered due to increased gene dosage on chromosome 21 and overproduction of superoxide dismutase (SOD-1 or Cu/Zn SOD). The purpose of this study was to investigate the activities of SOD-1 and glutathione peroxidase (GSH-Px) enzymes and the levels of their cofactors zinc (Zn), copper (Cu) and selenium (Se) in plasma of 20 Down syndrome patients. In comparison with age and sex-matched controls (n=15), plasma GSH-Px, SOD, and Cu levels were significantly decreased in the patient group, but Zn and Se concentrations remained unchanged. This study was presented as a poster in 29th Annual Meeting of European Society of Human Genetics held in Genoa in May, 1997.     

Determination of some elements in the cervical mucus of healthy Taiwanese women,by GF-AAS

The levels of seven trace elements such as copper, iron, zinc, selenium, cadmium, chromium, and nickel were determined by graphite furnace-atomic absorption spectrometry in the cervical mucus of 45 women residing in Taiwan, Republic of China. These women were in good health and had no precancerous or cancerous lesions on their cervix. The women were separated into four age groups to establish if there was a relationship between the age of the subjects and the values of these elements in the cervical mucus. By one-way analysis of variance, significant differences in the selenium and nickel concentrations were found among the four age groups (p<0.05). The mean concentration of selenium in each age group was significantly higher for the older women. A significant correlation between age and selenium concentration was found by linear regression (r=0.23, p=0.00048). No significant differences among the concentrations of copper, iron, zinc, cadmium, and chromium were found among these four age groups (p>0.05). The results presented in this work may be considered as baseline values for these elements in the cervical mucus of healthy Taiwanese women for use as reference in studies on cervical diseases and tissue damage.     

Trace mineral status in post menopausal women: impact of hormonal replacement therapy.

The risks of disturbances in trace mineral nutrition and metabolism are high following menopause. The aim of the study was to investigate the trace mineral status in postmenopausal women and the influence of hormonal replacement therapy on this status. Forty-four healthy postmenopausal women, aged 50-60 years old participated in the study. Eighteen were treated by combined hormonal replacement therapy (HRT) per os for at least two years, and 26 were untreated. Plasma trace mineral levels (Zn, Se, Cr, Mn, Cu), red blood cell antioxidant enzymes (Cu-Zn SOD, Se-GPX, Cu), urinary Zn, Cr, Mg, and Ca excretion were measured. Zinc, selenium and manganese plasma levels, activities of Cu-Zn-SOD and GSH-Px in erythrocytes were not statistically different between the two groups. The percentage of zinc plasma levels below the cut off of 10.7 micromol/L was higher in HRT treated group than in untreated one, whereas zinc excretion was reduced. Plasma copper concentrations were higher in women treated by HRT, whereas erythrocyte copper levels were not modified. Plasma chromium concentrations were significantly higher in women receiving HRT and urinary Cr excretion was decreased. The HRT group also exhibited lower losses of urinary zinc and magnesium than untreated women. These data suggest that hormonal replacement therapy provides beneficial effects on trace mineral status related to menopause.     

硒元素对平菇菌丝体GSH-Px、SOD及MDA的影响

于培养基中加入一定量的亚硒酸钠溶液 ,分别测定了 2个品种平菇菌丝体内GSH Px、SOD活性及MDA含量。结果表明 :3 0、60mg/L组菌丝体内GSH Px、SOD活性极显著升高 (P <0 .0 1 )而MDA含量明显降低 (P <0 .0 5 ) ,随着硒水平的升高 ,GSH Px、SOD活性呈下降趋势而MDA含量则显著升高 (P <0 .0 5 )。因此 ,在培养富硒平菇菌丝体时应适当考虑培养基的硒浓度。     

Plasma alpha-tocopherol, retinol, cholesterol, and mineral concentrations in captive gorillas

Vitamins A, E, cholesterol, and mineral (calcium, copper, iron, magnesium, phosphorus, selenium, sodium, and zinc) concentrations were examined in the plasma of 74 captive lowland gorillas aged newborn to 41 years. Effects of age or sex on measured parameters were not significant. Plasma Mg and Ca concentrations were lower than reported captive gorilla means, whereas Na and P were higher. Since comparative gorilla values for certain blood components (vitamins E and A, copper, and selenium) are lacking, normal human values may provide the best available indicators for evaluating the plasma levels of these components in gorillas.     

Selenium,Copper and Zinc in Seminal Plasma of Men with Varicocele,Relationship with Seminal Parameters

Varicocele has been associated with decrease in seminal parameters. Selenium (Se), copper (Cu), and zinc (Zn) are trace elements essential for normal spermatogenesis of mammals and play a critical role as antioxidant defense system enzymes. Se, Cu, and Zn are associated with sperm quality in fertile and infertile men. However, there is little information about Se, Cu, and Zn concentrations in semen in patients with varicocele and its association with seminal parameters. The purpose of this study was to determine the concentrations of Se, Cu, and Zn in semen of patients with varicocele and the relationship with seminal parameters. Total Reflection X-Ray Fluorescence was used for the fist time in the seminal fluid analysis. The concentration of selenium in men with varicocele was smaller than the normozoospermic group, while no differences were observed for both concentrations of zinc and copper. A significant positive correlation between zinc and selenium concentration was observed. Selenium in seminal plasma correlates with a good spermatozoa concentrations, motility, and morphology. Additionally, a significant positive correlation was observed between zinc levels and sperm count. In conclusion, a decrease in selenium concentration was associated with detriment of seminal parameters. A study should be conducted to evaluate the benefits of both zinc and selenium supplementation to improve seminal parameters in patients with varicocele.     

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.     

Red blood cell and plasma glutathione peroxidase activities and selenium concentration in patients with chronic kidney disease: a review

The metabolism of oxygen in aerobic organisms leads to generation of reactive oxygen species (ROS). These entities are able to oxidize almost all classes of macromolecules, including proteins, lipids and nucleic acids. The physiological level of ROS is usually regulated by antioxidant defense mechanisms. There are at least three groups of antioxidant enzymes: superoxide dismutases, catalases and glutathione peroxidases (GSH-Pxs) which neutralize ROS. The trace elements (copper, zinc and selenium) bound to the active sites of the above listed enzymes play an important role in the antioxidant defense system. In mammals, a major function of selenium (Se) and Se-dependent GSH-Pxs is to protect cells from oxidative stress. Selenium concentrations and GSH-Px activities are altered in blood components of chronic kidney disease (CKD) patients. The Se level is frequently lower than in healthy subjects and the concentration very often decreases gradually with advancing stage of the disease. Studies on red cell GSH-Px activity in CKD patients reported its values significantly lower, significantly higher and lower or higher, but not significantly as compared with healthy subjects. On the other hand, all authors who studied plasma GSH-Px activity have shown significantly lower values than in healthy subjects. The degree of the reduction decreases gradually with the progression of the disease. High inverse correlations were seen between plasma GSH-Px activity and creatinine level. A gradual decrease in plasma GSH-Px activity in CKD patients is due to the fact that this enzyme is synthesized predominantly in the kidney and thus the impairment of this organ is the cause of the enzyme's lower activity. Se supplementation to CKD patients has a slightly positive effect in the incipient stage of the disease, but usually no effect was observed in end-stage CKD. Presently, kidney transplantation is the only treatment that may restore plasma Se level and GSH-Px activity in patients suffering from end-stage CKD. A few studies have shown that in kidney recipients, plasma Se concentration and GSH-Px activity are restored to normal values within a period of 2 weeks to 3 months following surgery and thus it can be acknowledged that Se supplementation to those patients has a positive effect on plasma GSH-Px activity.