Serum Glutathione Peroxidase Activity and Blood Selenium in Pigs

Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs.     

Effects of Selenium Administration on Erythrocyte and Blood Plasma Glutathione Peroxidase Activity in Goats

The activity of glutathione peroxidase (GSH-Px, E.G. 1.11.1.9.) was determined in heparinized whole blood, blood plasma and washed erythrocytes from goats before and up to 4 weeks after the administration of selenium (0.4 mg/10 kg BW) and vitamin E (20 mg/10 kg BW) or only vit. E (20 mg/10 kg BW). It was found that Se administration caused a significant increase in enzyme activity in whole blood and washed erythrocytes first detected 2 weeks after the intramuscular injection of Se. No changes were observed in plasma from the treated animals. Minor and insignificant changes were seen in the vit. E treated control animals. It is concluded that GSH-Px activity in blood plasma or serum is of no value as a short-term indicator of the selenium status of goats but whole blood is a good indicator of the long-term status.     

Selenium and Vitamin E Deficiency in Pigs

The effect of selenium (Se) and vitamin E (Vit. E) on reproductive performance, growth and health was studied in pigs. Two levels of Se were used, 0.03 and 0.06 nag per kg feed. The major component of the experimental diets was barley originating from soil which had formerly produced crops with a very low content of Se. Prior to seeding, the area was divided into 2 plots, 1 of which was treated with Se in the form of sodium selenite, 100 g Se per ha. The use of Se enriched fertilizer was an effective way of increasing the Se concentration of the grain. Thus the concentration of Se in the barley produced on the treated area was 5 times higher than in barley from the untreated one. Vit. E was added at a level of 30 i.u. per kg feed, and the concentrations were approx. 15 and 45 i.u. in the basal and experimental diets, respectively. The higher level of Se or Vit. E was not significantly associated with milk yield of the sow, litter size, birth weight or haemoglobin levels. However, there was a tendency to an increase in milk yield of the sows following additions of Se plus Vit. E, and litter size was slightly higher from sows which had received an addition of Vit. E. The concentration of Se and Vit. E was much higher in colostrum than in sow milk, and additions of dietary Se and Vit. E were associated with marked increases in the concentrations of these compounds in both colostrum and sow milk. There was a moderately improving effect of a high Se concentration in feed on growth rate and feed utilization. Low dietary levels of Se and Vit. E were followed by increased mortality rate in piglets; iron toxicity in connection with iron treatment was observed in piglets on low dietary Vit. E. Symptoms characteristic of PSE were not observed in the Se and Vit. E deficient pigs.     

The Relationship of Erythrocyte Glutathione Peroxidase to Blood Selenium in Swine

The erythrocyte glutathione peroxidase activity and blood selenium have been investigated in swine fed a Se deficient diet with, and without, selenium supplementation. A highly significant correlation (r = 0.90) between erythrocyte glutathione peroxidase and blood selenium was found.     

Clinico-Pathologic Findings in Young Pigs Fed Different Levels of Selenium,Vitamin E and Antioxidant

A randomized, blocked 23 factorial experiment was conducted with 48 young pigs. The treatment factors were: 2 levels of selenium (55 and 115 µg/kg), 2 levels of vitamin E (3 and 53 mg/kg) and 2 levels of the antioxidant feed additive Ethoxyquin (0 and 150 mg/kg). All pigs were kept in single pens and fed ad libitum throughout the experimental period of 9 weeks, i.e. from 3 to 12 weeks of age. Plasma, heart, liver and muscle Se levels as well as whole blood glutathione peroxidase activity (EC 1.11.1.9 GSH-Px) were significantly higher in pigs given a dietary supplement of Se than in pigs given no supplement of Se (P ≤ 0.001). The Se-supplemented pigs showed a tendency to lower mean serum transaminase activity (ASAT and ALAT) than unsupplemented pigs, but the influence was significant (P ≤ 0.05) only for the ALAT activity. Blood vit. E levels were higher for pigs receiving a supplement of vit. E than for unsupplemented pigs (P ≤ 0.001), and so was the resistance of red blood cells against lipid peroxidation (ELP), as expressed by lower ELP values. There were no effects of Ethoxyquin supplementation on the biochemical variables included in the study. The histological examination of heart muscle showed that the score for changes was negatively influenced by both Se and vit. E supplement (P ≤ 0.001) and to some extent also by Ethoxyquin supplement (P ≤ 0.05). The histological picture of m. long dorsi was influenced only by the vit. E supplement (P ≤ 0.01). No histological changes were found in the liver in this study. There were inverse relationships between whole blood GSH-Px defluorescence time and blood Se, and between ELP and whole blood vit. E (P ≤ 0.001).     

Distribution of Selenium in Bovine Milk and Selenium Deficiency in Rats Fed Casein-based Diets,Monitored by Lipid Peroxide Level and Glutathione Peroxidase Activity

A major proportion of selenium in bovine milk was found in fluorometric analysis to be associated with the casein fraction, largely in alkali-labile form, and the rest with the whey fraction mostly in free selenite form. This uneven distribution of milk selenium seems to provide an explanation for selenium deficiency in purified caseins. The activity of glutathione peroxidase, a selenoprotein, in the liver of growing male rats fed ad libitum low-selenium diets containing either vitamin-free casein or Torula yeast 0.065 ± 0.012 or 0.015 ± 0.004 μ g Se/g diet, respectively) for 3 weeks decreased to 4 to 6% of that of the control rats fed a commercial stock diet (0.185 ± 0.092 μ g Se/g diet). Selenium status was evaluated by three different parameters for the rats assigned under pair-feeding regimen to those vitamin-free casein-based diets which were supplemented with graded levels of selenium as sodium selenite. The hepatic levels of the thiobarbituric acid-reactive substance, an indication of lipid peroxidation, decreased to control level with selenium supplementation per g diet of 0.1 μ g and over. The hepatic glutathione peroxidase activity reached a plateau above a 0.1 μ g/g diet of selenium supplementation, whereas the erythrocyte enzyme activity increased with increasing levels of supplementary selenium. These results support the notion that semi-purified diets containing vitamin-free casein as a prime protein source would not satisfy the selenium requirement of growing animals unless deliberately supplemented with additional selenium.     

Selenium and Glutathione Peroxidase Status in Adult Egyptian Patients with Acute Myeloid Leukemia

This study was undertaken to evaluate selenium (Se) and glutathione peroxidase (GPX) status in patients with newly diagnosed acute myeloid leukemia (AML) before and after induction therapy. Twenty-five patients with newly diagnosed AML and 15 healthy age- and sex-matched control subjects were included in this study. Serum Se level by the graphite furnace atomic absorption spectrometric technique and GPX activity by an adaptation of Beutler method was performed for the patients before and after receiving the induction therapy. Serum Se level was significantly lower in patients with AML versus control subjects (63.1?±?8.8 versus 77?±?8.8 µg/L before therapy with a P value <0.01 and 69?±?6.8 versus 77?±?8.8 µg/L after therapy with a P value <0.01).GPX activity was significantly lower in patients with AML versus control subjects (1.6?±?0.4 versus 3.4?±?0.7 µ/g protein pretreatment with a P value <0.01and 1.9?±?0.6 versus 3.4?±?0.7 µ/g protein post induction treatment with P value <0.01).Se level and GPX activity significantly increased in AML patients after treatment. Patients who accomplished complete remission after induction harbored significantly higher Se levels than resistant patients before and after treatment. There was no significant correlation between serum Se level and GPX activity. Decreased Se level and reduced GPX activity in AML patients support the association of carcinogenesis and subnormal Se states.     

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   

维生素E对三氯乙烯急性染毒大鼠肝脏脂质过氧化与抗氧化酶的影响

本文观察了用抗氧化剂维生素E预处理后,三氯乙烯(3000mg/kg B-W-) 一次性经口染毒24h 大鼠肝脏的超氧化物歧化酶、谷胱甘肽过氧化物酶等抗氧化酶活力及丙二醛含量的变化,结果表明三氯乙烯染毒组肝脏中丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均高于对照组(P< 0-01) ;而维生素E干预组的丙二醛含量、超氧化物歧化酶活力及血清谷丙转氨酶、谷草转氨酶活力均分别低于三氯乙烯染毒组(P< 0-01) ,说明三氯乙烯急性染毒可引起肝脏脂质过氧化反应及肝损害,肝脏超氧化物歧化酶活力升高可能是机体受自由基及脂质过氧化反应刺激而诱导产生的一种适应性反应,维生素E对三氯乙烯所致的肝损害有一定的保护作用。     

Erythrocyte Lipid Peroxidation and Antioxidants in Gastric Cancer Patients

The present study has analysed the relationship between lipid peroxidation and antioxidant status in erythrocytes from 24 adult male gastic cancer patients and an equal number of age- and sex-matched normal subjects. Erythrocyte lipid peroxidation was markedly increased. Both enzymic and non-enzymic antioxidants were decreased in erythrocytes of gastric cancer patients. The present study highlights the occurrence of lipid peroxidation and possible breakdown of antioxidant status in patients with gastric carcinoma. © 1997 John Wiley & Sons, Ltd.     

Selenium Levels and Glutathione Peroxidase Activity in Blood,Plasma and Reproductive Organs in Dairy Cows

Selenium levels and glutathione peroxidase activity were determined in blood and reproductive organs in 12 Norwegian dairy cows at different stages of the oestrus cycle. Blood samples were collected before slaughter, and samples from genital organs were obtained as soon as possible after slaughter. Blood and plasma selenium levels were significantly correlated with selenium levels in follicular fluid, and in ovarian and uterine tissues, but not with the levels in corpora lutea. The activity of blood glutathione peroxidase was significantly correlated with that in ovarian and uterine tissue, but not with activity in corpora lutea and follicular fluid. No effect of stage of oestrus cycle on selenium content or glutathione peroxidase in reproductive tissue was observed.     

Antioxidant Activity of Vitamin E and Trolox: Understanding of the Factors that Govern Lipid Peroxidation Studies In Vitro

Peroxidation of lipids is of significant interest owing to the evidence that peroxyl radicals and products of lipid peroxidation may be involved in the toxicity of compounds initiating a deteriorative reaction in the processing and storage of lipid-containing foods. In view of the significance of the antioxidant role of the dietary compound vitamin E and its water-soluble analogue Trolox in research of lipid-containing foods, it is desirable to determine more specifically how and where they operate its antioxidant activity in lipid membranes. In this study, unilamellar liposomes of phosphatidylcholine were used as membrane mimetic systems to estimate the antioxidant properties of vitamin E and Trolox and establish a relationship between their interactions with the membrane and their consequent antioxidant activity. Lipid peroxidation was initiated by the peroxyl radical (ROO^•) in lipid and aqueous media by the thermal decomposition of azocompounds and was assessed by the fluorescence intensity decay of the fluorescent probe diphenylhexatriene propionic acid. Results obtained showed that membrane lipoperoxidation is related not only to the scavenging characteristics of the compounds studied but also to their ability to interact with the lipid bilayers, and consequently liposomes provide additional information to that obtained currently from assays performed in aqueous buffer media.     

Selenium as Inducer of Glutathione Peroxidase in low-CO(2)-Grown Chlamydomonas reinhardtii

Culture of the green alga Chlamydomonas reinhardtii in the medium containing sodium selenite caused the activity of ascorbate peroxidase to disappear and the appearance of glutathione peroxidase. The induced maximum activity of glutathione peroxidase reached 350 micromole (milligram chlorophyll hour)⁻¹ under assay conditions used. The enzymic properties of the selenite-induced glutathione peroxidase closely resembled those of animal glutathione peroxidase that contains selenium.     

Selenium Concentration and Glutathione Peroxidase (GSH-Px) Activity in Serum of Cows at Different Stages of Lactation

The aim of the study was to evaluate the activity of glutathione peroxidase (GSH-Px) and the concentration of selenium in Holstein-Friesian cows at different stages of lactation. Selenium was determined spectrofluorimetrically and GSH-Px activity using a Sigma CGP1 Glutathione Peroxidase Cellular Activity Assay kit. Mean serum selenium concentration was highest in early-lactation multiparous cows (0.18 μg/ml) and the lowest in dry cows (0.111 μg/ml). In early lactation, serum selenium concentration was significantly (P ≤ 0.01) higher in multiparous cows than in cows from the other groups. Mean GSH-Px activity in the serum of dry cows was over twice lower than in late-lactation cows (P ≤ 0.01) and over four times lower than in first-calving heifers and multiparous cows in early lactation (P ≤ 0.01). The coefficients of Spearman's rank correlation between GSH-Px activity and selenium concentration in the cows at different stages of lactation were not significant. A significant (P ≤ 0.01) mean positive correlation (0.46) was found between GSH-Px activity and serum selenium concentration for all the cows analysed together. The highest Se concentration and GSH-Px activity found in the serum of cows during the first stage of lactation may suggest that the generation of reactive oxygen species and their derivatives was higher during this period compared to the other stages, thus placing the cows at a greater risk of oxidative stress. It is therefore essential to give particular attention during this period to meeting the cows' requirement for selenium and other feed components that increase, directly or indirectly, the capacity of the body's antioxidant system.     

Antioxidant Activity of 5-Hydroxytryptophan, 5-Hydroxyindole, and Dopa Against Microsomal Lipid Peroxidation and Its Dependence on Vitamin E

The antioxidant capacity of 5-hydroxy-tryptophan. 5-hydroxy-indole. and DOPA (3,4-dihydroxy-phenyI-alanine) was tested in the Fe-induced lipid peroxidation of liver microsomes of normal- and vitamin E-deficient rats, using ascorbate as a reductant. Lipid peroxidation was monitored as low-level chemilu-minescence, indicative of generation of electronically-excited states arising from the recombination of secondary lipid peroxyl radicals.     

Forms of Selenium Affect its Transport, Uptake and Glutathione Peroxidase Activity in the Caco-2 Cell Model

The aim of this study was to investigate the possible time- and dose-dependent cytotoxic effects of cobalt chloride on Vero cells. The cultured cells were incubated with different concentrations of cobalt chloride ranging from 0.5 to 1,000 μM, and cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and resazurin assays. Possible protective effects of vitamin E, coenzyme Q(10), and zinc chloride were also tested in this system. A gradual decrease in cell proliferation was observed at concentrations ~≥ 200 μM in incubation periods of 24, 48, 72, and 96 h with MTT assay. Exposure of cells to 500 and 1,000 μM cobalt chloride caused significant decrease in cell survival. A biphasic survival profile of cells was observed at 1-25 μM concentration range following 96 h of incubation. With resazurin assay, cytotoxicity profile of CoCl(2) was found comparable to the results of MTT assay, particularly at high concentrations and long incubation periods. Dose-dependent cytotoxicity was noted following exposure of cells to ≥ 250 μM of CoCl(2) for 24 h and ≥ 100 μM concentrations of CoCl(2) for 48-96 h. Pretreatment of cells with ZnCl(2) for 4 or 24 h provided significant protection against cobalt chloride-induced cytotoxicity when measured with MTT assay. However, vitamin E or coenzyme Q(10) was not protective. CoCl(2) had dose- and time-dependent cytotoxic effects in Vero cells. Preventive effect of ZnCl(2) against CoCl(2)-induced cytotoxicity should be considered in detail to define exact mechanism of toxicity in Vero cells.     

Tissue Specific Expression of Glutathione S-transferases, Glutathione Content and Lipid Peroxidation in Camel Tissues

Differential expression of glutathione S-transferase (GST) enzyme activity in various tissues of the camel was observed with a maximum activity in the liver. Compared with the rat and human livers, GST activity in camel liver was 50% lower than that of rat liver and similar to that of human liver. Extrahepatic tissues in camel have a comparable GST activity with those of similar tissues in the rat. Assay of GST activity using ethacrynic acid as substrate demonstrated maximum activity in the camel brain followed by intestine, liver and kidney. Microsomal GST activity in camel tissues was expressed in the order of liver > testis > intestine ≈ kidney ≈ brain. Phenotyping of GST was performed in camel hepatic and extrahepatic tissues using human specific antibodies to class α, μ, and π cytosolic GST isoenzymes and rat specific antibody to the microsomal GST. Western immunoblot and immunohistochemical analyses showed an abundant expression of GST α and μ in the camel liver, while π was very poorly expressed. Camel extrahepatic tissues however, had a significant expression of GST π. The camel GST isoenzymes were found to be predominantly expressed in the hepatocytes around the central vein with a gradual decrease in expression in the hepatocytes located toward the periphery. Kidney cortex exhibited a greater expression of the enzyme protein in the proximal tubules as compared to the glomeruli. Glutathione (GSH) concentration in rat tissues, except in the brain, was about 2-fold higher than that of camel tissues. Rate of NADPH-dependent microsomal lipid peroxidation was comparable both in the rat and camel tissues with the highest activity in the brain and lowest activity in the intestine. The differential expression of GST isoenzymes in different organs of the camel, GSH concentration and the rate of lipid peroxidation in different tissues may be important factors in determining the differential susceptibility of camel tissues to the toxic effects of xenobiotics.