Red Blood Cell GSH-Px Research Articles

Glutathione peroxidase activity in different breeds and sexes of chickens during embryonic development up to peak of egg production

Glutathione peroxidase (GSHPx) activity was investigated in the liver, red blood cells (RBC) and blood plasma (BP) of different chicken genotypes. Signifi cant differences among genotypes and age groups were found in liver GSHPx activity during embryonic development and in day-old chickens. Breed, sex and age effects were found in RBC and BP from one day of age until peak egg production. A negative correlation was found between embryo liver GSHPx activity and egg weight (-0.24; P≤0.01), between RBC and BP GSHPx activity and body weight (-0.32 and -0.44; P≤0.01), and between liver and RBC GSHPx activity (-0.54; P≤0.01), while positive correlations were demonstrated between liver and BP (0.66; P≤0.01) and BP and RBC (0.32; P≤0.01) GSHPx activity. In conclusion, variation in GSHPx activities in different chicken breeds during development suggests that it is genetically regulated. This fi nding indicates that GSHPx activity may be useful in selection.

Altered antioxidant defense system in clinically stable patients with schizophrenia and their unaffected siblings

Objective To determine Red Blood Cell (RBC) antioxidant enzyme activities and plasma Thiobarbituric Acid Reactive Substances (TBARS) in clinically stable patients with schizophrenia and their unaffected siblings. Methods A case-control study carried out on three groups: 60 schizophrenic patients treated with neuroleptics, 33 of their unaffected siblings and 30 healthy controls with no family psychiatric history. Biological markers were measured on fasting patients after a period of tobacco abstinence: RBC antioxidant enzyme activities – superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) – by spectrophotometry and plasma levels of TBARS by spectrofluorimetry. Results RBC SOD and CAT activities were significantly lower in schizophrenic patients and their unaffected siblings compared to the control group ( P < 0.001). Schizophrenic patients also had significantly lower RBC GSH-Px activity than controls ( P = 0.03), whereas their unaffected siblings had significantly higher RBC GSH-Px activity than controls ( P = 0.04). Plasma TBARS were higher in schizophrenic patients than their unaffected siblings: 2.1 ± 0.8 μmol/l vs. 1.7 ± 0.6 μmol/l ( P = 0.06). Conclusions Our results showed a decrease in antioxidant enzyme activities and an increase in lipid peroxidation confirming the existence of oxidative stress in schizophrenic patients treated with neuroleptics. Additionally, this suggests that the increase in GSH-Px activity in unaffected siblings would be a protective mechanism against oxidative stress and damage. Other studies are necessary to confirm these findings.

Blood α-Tocopherol, Selenium, and Glutathione Peroxidase Changes and Adipose Tissue Fatty Acid Changes in Kittens with Experimental Steatitis (Yellow Fat Disease): A Comparative Study Between the Domestic Shorthaired and Siamese Breed

Twenty domestic shorthaired (DSH) and 20 Siamese (S) kittens were allocated into 4 breed-specific groups, of 10 kittens each, that were fed exclusively cooked sardines (F groups) or commercial feline canned food based on oily fish (C groups) for a 4-month period. Clinical signs were scored every 15 d along with body weight recording and blood sampling for the measurement of alpha-tocopherol and selenium (Se) concentrations and glutathione peroxidase (GSH-Px) activity. Subcutaneous adipose tissue samples were obtained per month to determine its fatty acid composition. Steatitis, reproduced in all 20 F-group kittens, was accompanied by systemic signs in 5 DSH and 6 S animals. The severity of the disease reached its zenith at the second week in the DSH-F-group kittens and the fourth and sixth week in the S-F-group kittens. alpha-Tocopherol plasma level was significantly lower in F groups compared to their corresponding controls, whereas the opposite was true for Se and red blood cell GSH-Px activity. In conclusion, the results of this study have shown that although the morbidity rate is not different between the two breeds, the delay of Siamese cats to develop symptomatic steatitis is presumably attributed to an inherent resistance as a result of the long-standing evolution of more efficient antioxidant mechanisms. Also, the changes in fatty acid composition of the adipose tissue lipids are associated with the progression of the age, breed, and diet and probably with the inflammatory changes of the adipose tissue.

Glutathione and Glutathione Peroxidase Activities in Blood of Patients in Early Stages Following Kidney Transplantation

This study focuses on glutathione (GSH) level in red blood cells, as well as on glutathione peroxidases (GSH-Px) activities in red blood cells and in plasma of chronic renal failure (CRF) patients following renal transplantation. We want to focus our main attention on plasma GSH-Px, the selenoenzyme that is synthesized primarily in the kidney. In CRF patients, activity of this enzyme is significantly reduced, and the reduction decreases with the progress of the disease, reaching in the end-stage 20% to 30% of the activity of healthy patients. We have shown that following renal transplantation the activity of plasma GSH-Px is restored very rapidly, and 2 weeks after surgery it reached the value of the control group. Red blood cell GSH level is significantly higher in CRF patients, and following transplantation, no significant changes were observed. Red blood cell GSH-Px activity before transplantation was the same as in healthy patients and did not change significantly after surgery.

Determination of the selenium requirement in kittens.

The purpose of this study was to determine the selenium (Se) requirement in kittens. Thirty-six specific-pathogen-free kittens (9.8 weeks old) were utilized in a randomized complete block design to determine the Se requirement in cats with gender and weight used as blocking criteria. Kittens were fed a low Se (0.02 mg/kg Se) torula yeast-based diet for 5 weeks (pre-test) after which an amino acid-based diet (0.027 mg Se/kg diet) was fed for 8 weeks (experimental period). Six levels of Se (0, 0.05, 0.075, 0.10, 0.20 and 0.30 mg Se/kg diet) as Na2SeO3 were added to the diet and were used to construct a response curve. Response variables included Se concentrations and Se-dependent glutathione peroxidase activities (GSHpx) in plasma and red blood cells (RBC) as well as plasma total T3 (TT3) and total T4 (TT4). No significant changes in food intake, weight gain or clinical signs of Se deficiency were noted. Estimates of the kitten's Se requirement (i.e. breakpoints) were determined for RBC and plasma GSHpx (0.12 and 0.15 mg Se/kg diet, respectively), but no definitive breakpoint was determined for plasma Se. Plasma TT3 increased linearly, whereas plasma TT4 and the ratio of TT4 : TT3 decreased in a quadratic fashion to dietary Se concentration. The requirement estimate determined in this study (0.15 mg Se/kg) for kittens is in close agreement with other species. As pet foods for cats contain a high proportion of animal protein with a Se bioavailability of 30%, it is recommended that commercial diets for cats contain 0.5 mg Se/kg DM.

Adenosine deaminase enzyme activity is increased and negatively correlates with catalase, superoxide dismutase and glutathione peroxidase in patients with Behçet's disease: original contributions/clinical and laboratory investigations.

AIM: Behçet's disease (BD) is an inflammatory vasculitis with immunologic, endothelial and neutrophil alterations. Adenosine deaminase (AD) is a marker of T-cell activation and is related to the production of reactive oxygen species by neutrophils with the production of NO(*), O(2)(*-), H(2)O(2) and OH(*). We reported increased tumour necrosis factor-alpha, soluble interleukin-2 receptor, interleukin-6, interleukin-8 and NO(*) in active BD. As there is a relation between cytokines, T cells and oxidative stress in inflammatory diseases, this study further evaluated: (1) plasma AD activity and its correlation with acute phase reactants; (2) thiobarbituric acid-reactive substances (TBARS) as an indicator for lipid peroxidation; and (3) antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSHPx) and catalase in patients with BD. The effect of disease activity and correlations between the measured parameters were explored. METHODS: A total of 35 active (n=17) or inactive (n=18) patients with BD (16 men, 19 women) satisfying International Study Group criteria, and 20 age-matched and sex-matched controls (nine men, 11 women) were included in this cross-sectional case-control study. AD and TBARS were measured in plasma, catalase in red blood cells (RBC), and SOD and GSHPx in both plasma and RBC in both groups. Acute phase reactants (alpha(1)-antitrypsin, alpha(2)-macroglobulin, neutrophils, erythrocyte sedimentation rate) were used to classify patients as active or inactive. RESULTS: Plasma AD (mean+/-standard error of the mean, 36.1+/-0.7 U/l) and TBARS (4.2+/-0.1 nmol/ml) levels were significantly (for each, p<0.001) higher in BD than in controls (24.1+/-0.8 U/l and 1.6+/-0.1 nmol/ml, respectively). RBC catalase activity was significantly (p<0.001) lower in BD than in controls (120.9+/-3.8 versus 160.3+/-4.1 k/g haemoglobin). SOD and GSHPx activities were significantly lower in both plasma and erythrocytes of patients with BD than in controls (plasma SOD, 442.4+/-8.6 versus 636.4+/-9.2 U/ml, p<0.001; RBC SOD, 3719.2+/-66.0 versus 4849.7+/-49.0 U/g haemoglobin, p<0.001; plasma GSHPx, 73.1+/-1.5 versus 90.6+/-2.9 U/ml, p<0.001; RBC GSHPx, 600.7+/-8.0 versus 670.6+/-10.1 U/g haemoglobin, p<0.001). Active BD patients had significantly lower antioxidant enzymes (except RBC catalase) and higher AD and TBARS levels than inactive subjects (for each, p<0.01). When considering all BD patients, a significant positive correlation was present between AD and TBARS (p<0.001) whereas both AD and TBARS were negatively correlated with antioxidant enzymes (for each, p<0.05). CONCLUSIONS: AD and lipid peroxidation are increased and associated with defective antioxidants in BD, suggesting interactions between activated T cells and neutrophil hyperfunction. Measures of pro-oxidative stress and antioxidative defence with AD activity as an indicator of T-cell activation can be considered as significant supportive diagnostic indicators, especially in active disease. In addition, strengthening the antioxidant defence may contribute to treatment modalities.

Effects of pre- or postpartum selenium supplementation on selenium status in beef cows and their calves.

The effect of Se supplementation before or after calving on Se status in deficient cows and their calves was studied using 72 beef cows in two experiments. In Exp. 1, cows calving in February or March 1997 were supplemented orally for 15 d in late pregnancy with 13.0, 32.5, or 45.5 mg of Se/d as sodium selenite. Glutathione peroxidase (GSH-Px) activities were measured in red blood cells (RBC) or plasma of cows and calves at d 15 and between d 17 and 88 after calving. In Exp. 2, cows calving in January 1997 were supplemented orally with .0, 13.0, or 32.5 mg of Se/d for 15 d postpartum, and calves were injected with 1.38 mg of Se when 2 d old and at an average age of 49 d. The GSH-Px activities were measured in 30-d-old calves and in cows and calves between d 77 and 115 after calving. In both experiments, Se supplementation resulted in adequate Se status for the dams. The increase in RBC GSH-Px activity was faster with 45.5 mg of Se/d, and GSH-Px activities remained high for up to 98 d after the end of supplementation. The improvement in Se status in calves as a result of maternal supplementation was greater in Exp. 1 than in Exp. 2, suggesting that the placental transfer of Se is more efficient than milk transfer. Prepartum oral Se supplementation of deficient beef cows with 13.0 mg of Se/d for 15 d allowed adequate Se status of dams and calves, and 45.5 mg of Se/d resulted in a faster improvement of Se status. Parenteral administration of 1.38 mg of Se to newborn calves did not sustain normal Se status in calves issued from deficient cows.

Antioxidant status in asthma

Reduced levels of glutathione peroxidase (GSH-Px) have been observed in adults with asthma. This study examines the antioxidant status in children with asthma compared with a control group in a cross-sectional analysis. Red blood cell GSH-Px, superoxide dismutase (SOD), and plasma concentrations of retinol, vitamin C, alpha tocopherol, and cholesterol were measured in 37 subjects (26 males) with stable controlled asthma. Thirty-five subjects (20 males) without eczema, hayfever, or recurrent respiratory symptoms were used as a control group. Children with asthma had significantly reduced red blood cell GSH-Px activity compared with controls [median (inter-quartile range) for asthma group, 10.25 (9.25-11.91); for control group, 11.75 (10.34-12.26) IU/g Hb; P = 0.006]. There were no significant differences in activity of SOD or vitamin C, retinol, or alpha tocopherol/cholesterol ratio. The reduction in GSH-Px activity may have therapeutic and etiological implications for asthma. The effects of disease activity and treatment on antioxidant status needs for further study.

Red Blood Cell Susceptibility to Lipid Peroxidation, Membrane Lipid Composition, and Antioxidant Enzymes in Continuous Ambulatory Peritoneal Dialysis Patients

To investigate the overall susceptibility of red blood cells (RBC) to lipid peroxidation from patients on continuous ambulatory peritoneal dialysis (CAPD). The following parameters were measured: RBC malondialdehyde (MDA) production after oxidative stress with H2O2, RBC antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), and RBC membrane lipid composition. The levels of plasma vitamin E and serum selenium were also assayed. Eleven patients on continuous ambulatory peritoneal dialysis. Twenty-one healthy blood donors of similar age were used as normal controls. The MDA formation after H2O2 stimulation was normal in CAPD patients (0.79 +/- 0.1 mumol/gHb versus 0.78 +/- 0.1 in the control group). RBC from CAPD patients also showed a normal SOD activity, a more than adequate vitamin E status, and a peculiar pattern of membrane lipids, with reduced polyunsaturated fatty acids (p less than 0.001) and increased monounsaturated fatty acids (p less than 0.001). Both RBC GSH-Px activity, a selenium-dependent enzyme, and serum selenium levels were significantly lower in CAPD patients, and a significant positive correlation (r = 0.68; p less than 0.02) between the two parameters was found. This study found a normal sensitivity to oxidant stress in RBC from a group of CAPD patients, despite an impaired GSH-Px activity. The peculiar lipid pattern of RBC membrane, characterized by reduced PUFA and increased MUFA content, may contribute, in addition to adequate SOD activity and vitamin E status, to normal RBC lipid peroxidation.

Erythrocyte Glutathione Peroxidase and Myocardial Infarction

To the Editor.— I read with interest the article by Kok et al. 1 The authors state that data on erythrocyte (red blood cell) glutathione peroxidase (GSH-Px) (EC 1.11.1.9) activity in patients who have had a myocardial infarction have not been published. We are working on this problem. It is known that GSH-Px is one of the major enzymes involved in the protection of the cell against antiperoxidation, particularly the cells of heart muscle. Selenium-containing GSH-Px acts on hydrogen peroxide and lipids or other organic hydroperoxides. 2 Doroshow et al 3 found that in heart tissue catalase was almost absent and superoxide dismutase had only 27% of the activity found in liver. Only GSH-Px activity is high both in liver and in heart tissues. Batist et al 4 demonstrated that changes in this enzyme in heart cells and in erythrocytes are well correlated. Study.— We determined red blood cell GSH-Px

Glutathione peroxidase and selenium deficiency in patients receiving home parenteral nutrition: time course for development of deficiency and repletion of enzyme activity in plasma and blood cells

The time course for the depletion of red blood cell (RBC) and plasma glutathione peroxidase (GSHPx) activity in five patients receiving home parenteral nutrition was documented. During the development of the RBC GSHPx deficiency, enzymatic activity and protein content decreased. Plasma and RBC selenium content were similarly decreased as was cellular metabolism of exogenous hydrogen peroxide. When the replacement of Se (selenious acid) began, there was a rapid increase (within 6 h) in plasma GSHPx activity. Platelet and granulocyte (PMN) GSHPx activity, which were low when Se replacement began, became normal within a time consistent with the kinetics of platelet and PMN production. RBC GSHPx did not become normal for 3-4 mo. This is consistent with the time course for RBC production. It appears that the repletion of blood cell GSHPx requires the formation of these cells in the presence of Se.

Subnormal concentrations of serum selenium and plasma carnitine in chronically tube-fed patients

Forty-seven tube-fed nursing home patients were investigated with regard to serum or plasma selenium (Se), carnitine, and red blood cell (RBC) glutathione peroxidase (GSH-Px). Thirty-six patients were tube fed with Isocal, and 11 were tube fed with Compleat B, an L-carnitine-containing formula. Eighteen elderly nursing home patients and 10 young adults served as controls. Serum Se and plasma carnitine were lowest (p less than 0.05) in the Isocal patients. In all 36 Isocal subjects, Se was below normal, and in 26% of Isocal patients RBC GSH-Px was also below normal. Free and total carnitine were below normal in most Isocal subjects. All 11 Compleat B patients had subnormal serum Se, but most had normal carnitine concentrations. These data suggest that enteral formulae in nursing homes should contain greater than 100 micrograms Se and on the order of a mmol carnitine/1600 kcal.

The selenium status of Belgian population groups

A moderate level of selenium (Se) was demonstrated in the blood (123 ng/mL), erythrocytes (RBC) (161 ng/mL), and plasma (97 ng/mL) of 110 male and 54 healthy female Belgian adults by using hydride-generation atomic absorption spectrometry. These values agree well with those found in neighboring countries. The study is the first one to report on normal values for these parameters in Belgians.Glutathione peroxidase (GSH-Px) activity has also been assayed. The group in considered nondeficient. Neither the concentration of Se in blood, plasma, or RBC, nor the activity of GSH-Px in the latter, were related to age, sex, blood pressure, or smoking habits. Oral contraception was associated with elevated plasma Se levels as compared to controls (P<0.01).A statistically significant positive relationship existed between the Se concentrations in whole blood or in red blood cells and red blood cell GSH-Px activity (r=0.31,p<0.005).

The Effect of Mercury and Vitamin E on Tissue Glutathione Peroxidase Activity and Thiobarbituric Acid Values3

The effects of methyl mercuric chloride (CH3HgCl) and mercuric chloride (HgCl2) on red blood cell (RBC), plasma, and liver glutathione peroxidase (GSH-Px) activities were determined in Japanese quail fed a semipurified diet with 1 ppm added selenium (Se). The RBC GSH-Px activity was significantly increased by 5 ppm mercury (Hg) as CH3 HgCl. Plasma GSH-Px activity was significantly depressed only in the 20 ppm Hg group. Liver GSH-Px activity was not affected. The RBC GSH-Px activity was significantly lower at all levels of HgCl2 compared to the CH3 HgCl-treated birds. Plasma and liver GSH-Px activity of the HgCl2 -treated birds were not significantly different from control values.In a second experiment, GSH-Px activity and estimate s of peroxidation via the thiobarbituric acid (TBA) test were determined on quail fed diets containing .07 ppm added Se to which either 10 ppm Hg as CH3 HgCl or 150 ppm Hg as HgCl2 were added with or without the supplementation of vitamin E. Plasma and kidney GSH-Px activities were unaffected by CH3 HgCl, whereas RBC GSH-Px was significantly elevated. Kidney GSH-Px was significantly depressed by HgCl2. Vitamin E had no effect on GSH-Px activities. Vitamin E protected the liver, kidney, and brain from peroxidation; however, peroxidation was not induced by either of the mercurials.

Nutritional Availability to Rats of Selenium in Tuna, Beef Kidney, and Wheat

Weanling male rats were fed a selenium (Se)-deficient 40% Torula yeast diet for 4 weeks and were then continued on depletion for another 4 weeks or were repleted with 0.1, 0.2, or 0.3 ppm Se as sodium selenite or 0.2 ppm Se as tuna, beef kidney, or high-Se wheat. There were no significant differences in young red blood cell Se, unfractionated red blood cell Se, or liver Se levels in groups fed diets containing 0.2 ppm Se. Glutathione peroxidase (GSH-Px) activity in young red blood cells was lower in the three groups fed food Se than in the group fed selenite (0.2 ppm Se). Young red blood cell GSH-Px was significantly lower in rats fed tuna than in rats fed wheat. Unfractionated red blood cell GSH-Px was lower in rats fed tuna than in rats fed selenite, but did not differ significantly among groups fed food Se sources. Liver GSH-Px was significantly lower in rats fed tuna than in rats fed kidney, wheat, or selenite. Availability of Se was only 54–58% as great from tuna as from selenite for induction of GSH-Px in liver and in red blood cell populations. Therefore, low availability of Se from fish may have to be considered when assessing Se status of human beings from dietary intake.Selenium selenium bioavailability glutathione peroxidase tuna mercury

Glutathione Peroxidase Activity in Iron-Deficient Rats

The response of glutathione peroxidase (GSH-Px) to dietary iron deficiency was studied in red blood cells and liver from male Sprague-Dawley rats. A casein-based purified diet containing 0.02 ppm Se and 7 ppm Fe was used as the basal diet. Rats were given the basal diet supplemented with either 0.5 ppm Se or 30 ppm Fe or both for 10 weeks. Food consumption in irondeficient rats was 79% of controls. Iron deficiency caused a significant decrease of GSH-Px and catalase activities in red blood cells (RBC) expressed per cell. However, enzyme activities expressed per gram of hemoglobin or per milligram of protein increased. These data suggest that GSH-Px is present in adequate quantities in iron-deficient red blood cells to protect cell membranes and hemoglobin as long as the rats receive adequate Se. Hepatic catalase was not altered by iron or Se deficiency. Liver Se GSH-Px activity/g tissue decreased to 75% of control activity during iron deficiency. Non Se GSH-Px activity increased during Se or iron deficiencies and may compensate to a limited extent for decreased Se GSH-Px activity. In contrast to earlier reports, RBC GSH-Px activity was not altered by iron deficiency except for possible indirect effects related to changes in red blood cell size or food intake.iron deficiency glutathione peroxidase

Neonatal erythrocyte glutathione peroxidase deficiency as a consequence of selenium imbalance during pregnancy.

The red blood cell (RBC) glutathione peroxidase (GSH-Px) activity and routine haematological parameters were measured in 38 healthy north Italian full-term pregnant women and in their newborn infants. In 31 pairs the serum selenium concentration was also measured. Data were compared with those of 20 normal adult controls (10 males and 10 females). Newborn infants exhibited significantly lower RBC GSH-Px activity and serum selenium concentrations than adult controls. Pregnant women had serum selenium values intermediate between those of adult female controls and their newborn infants. In both the pregnant women and newborns the RBC GSH-Px activity correlated with the level of selenium in serum which suggests that the neonatal RBC GSH-Px deficiency may be partially due to insufficient availability of selenium during pregancy. Factors other than selenium concentration, e.g. hormonal and genetic, might also affect the RBC GSH-Px activity as suggested by sex differences and mother/child concordances in enzyme activity found in our cases.