Kinetic studies on the glutathione peroxidase activity of selenium-containing glutathione transferase

Author(s):  
Huijun Yu ◽  
Junqiu Liu ◽  
Xiaoman Liu ◽  
Tianzhu Zang ◽  
Guimin Luo ◽  
...  
1998 ◽  
Vol 864 (1 ENZYME ENGINE) ◽  
pp. 280-283 ◽  
Author(s):  
SHU-JUAN GAO ◽  
MO CHEN ◽  
WEI LIN ◽  
GUI-MIN LUO ◽  
JIA-CONG SHEN

Author(s):  
K. Dvorshchenko ◽  
O. Korotkiy ◽  
D. Grebinyk ◽  
Ye. Torgalo

The goal of this work was the research of chondroitin sulfate prophylactic action on the glutathione system state in rat blood serum during acute joint inflammation. The research was performed on white non-linear pubertal rat males weighting 160-240 grams in compliance to all general ethical principles of animal research. All animals were divided to four experimental groups. The first group – the control: the animals were injected with 0,1 ml of 0,9 % NaCl solution in a right hind leg. The second group – rats were subjected to daily intramuscular injections of 3 mg/kg of chondroitin sulfate in the theurapeutic dose during 28 days. The third group – the animals were subjected to daily doses of 0,1 ml of 0,9 % NaCl solution injected in right hind extremities and starting from 29th day the acute joint inflammation was modelled (the animals were subjected to 0,1 ml of 1% of сarrageenan intramuscular injection in right hind extremities. The fourth group – rats were receiving intramuscular injections of therapeutic dose of 3 mg/kg of chondroitin sulfate for 28 days, and after that the acute joint inflammation was modelled starting from 29th day. 40 animals in all were taking part in the experimental research. The glutathione peroxidase activity was assessed judging from the decrease in GSH amount in the reaction with Ellman reagent. The glutathione peroxidase activity was estimated by the decrease in probe optical density owing to NADPH oxidation. Glutathione transferase activity was estimated by the speed of the conjugate formation between GSH and 1-chloro-2,4-dinitrobemzene. The amount of reduced glutathione was estimated spectrophotometrically using orthophthalic aldehyde. It was established that during the carrageenan-induced inflammation the glutathione peroxidase, glutathione reductase and glutathione reductase activity were reduced, a well as the amount of reduced glutathione, whereas the glutathione transferase activity was increased in comparison to the control. It was shown that under the prophylactic injection of the chondroitin sulfate based preparate to animals with acute joint inflammation the aforementioned parameters were partially stabilized.


2020 ◽  
Vol 12 (1) ◽  
pp. 31-38
Author(s):  
Halyna Kopylchuk ◽  
Ivanna Nykolaichuk

The article is devoted to the study of the main components of the glutathione system under conditions of toxic damage against the background of nutritional protein deficiency: the content of reduced and oxidized glutathione with the determination of the GSH/GSSG ratio, the activity of glutathione-dependent enzymes – glutathione peroxidase, glutathione transferase, glutathione reductase, and glucose-6-phosphate dehydrogenase. The concentration of reduced glutathione in the erythrocyte hemolysate was studied using Elman's reagent after deproteinization of the samples. Glutathione transferase activity was determined by the rate of formation of glutathione S conjugates by reacting reduced glutathione with a substrate of 1-chloro-2.4-dinitrobenzene. Glutathione peroxidase activity was evaluated by the formation of oxidized glutathione. The activity of glutathione reductase in erythrocytes was determined by the method, is based on measuring the oxidation rate of NADPH+H+, which is recorded by decreasing absorption at a wavelength of 340 nm. A decrease in the ratio of GSH/GSSG in rat erythrocytes under conditions of toxic damage against a nutritional deficiency of protein is indicated by a functional shift in the thiol-disulfide balance towards increased use of the reduced form of glutathione for antioxidant protection. It was established that toxic damage is a key factor in reducing the level of glutathione transferase against the background of an increase in glutathione peroxidase activity in rat erythrocytes, the activation of which probably prevents the progression of LPO processes. At the same time, under conditions of toxic damage, against the background of alimentary protein deficiency, a decrease in glutathione reductase and glucose-6-phosphate dehydrogenase activity is observed, which leads to blocking of the first stage of glucose-6-phosphate metabolism in the pentose phosphate cycle, resulting in a decrease in the amount of NADPH and, accordingly reduced glutathione.


1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Itana Gomes Alves Andrade ◽  
Fabíola Isabel Suano-Souza ◽  
Fernando Luiz Affonso Fonseca ◽  
Carolina Sanchez Aranda Lago ◽  
Roseli Oselka Saccardo Sarni

Abstract Introduction Ataxia-Telangiectasia (A-T) is a multi-system disorder that may be associated with endocrine changes, oxidative stress in addition to inflammation. Studies suggest that selenium is a trace element related to protection against damage caused by oxidative stress. Objective To describe the plasma levels of selenium and erythrocyte glutathione peroxidase activity in A-T patients and to relate them to oxidative stress and lipid status biomarkers. Methods This is a cross-sectional and controlled study evaluating 22 A-T patients (age median, 12.2 years old) matched by gender and age with 18 healthy controls. We evaluated: nutritional status, food intake, plasma selenium levels, erythrocyte glutathione peroxidase activity, lipid status, inflammation and oxidative stress biomarkers. Results Adequate levels of selenium were observed in 24/36 (66.7%) in this evaluated population. There was no statistically significant difference between the groups in selenium levels [47.6 μg/L (43.2–57.0) vs 54.6 (45.2–62.6) μg/dL, p = 0.242]. Nine of A-T patients (41%) had selenium levels below the reference value. The A-T group presented higher levels of LDL-c, non-HDL-c, oxidized LDL, Apo B, Apo-B/Apo-A-I1, LDL-c/HDL-c ratio, malondialdehyde [3.8 µg/L vs 2.8 µg/L, p = 0.029] and lower Apo-A-I1/HDL-c and glutathione peroxidase activity [7300 U/L vs 8686 U/L, p = 0.005]. Selenium levels were influenced, in both groups, independently, by the concentrations of oxidized LDL, malonaldehyde and non-HDL-c. The oxidized LDL (AUC = 0.849) and ALT (AUC = 0.854) were the variables that showed the greatest discriminatory power between groups. Conclusion In conclusion, we observed the presence of selenium below the reference value in nearly 40% and low GPx activity in A-T patients. There was a significant, inverse and independent association between selenium concentrations and oxidative stress biomarkers. Those data reinforce the importance of assessing the nutritional status of selenium in those patients.


1989 ◽  
Vol 264 (3) ◽  
pp. 737-744 ◽  
Author(s):  
P Steinberg ◽  
H Schramm ◽  
L Schladt ◽  
L W Robertson ◽  
H Thomas ◽  
...  

The distribution and inducibility of cytosolic glutathione S-transferase (EC 2.5.1.18) and glutathione peroxidase (EC 1.11.1.19) activities in rat liver parenchymal, Kupffer and endothelial cells were studied. In untreated rats glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and 4-hydroxynon-2-trans-enal as substrates was 1.7-2.2-fold higher in parenchymal cells than in Kupffer and endothelial cells, whereas total, selenium-dependent and non-selenium-dependent glutathione peroxidase activities were similar in all three cell types. Glutathione S-transferase isoenzymes in parenchymal and non-parenchymal cells isolated from untreated rats were separated by chromatofocusing in an f.p.l.c. system: all glutathione S-transferase isoenzymes observed in the sinusoidal lining cells were also detected in the parenchymal cells, whereas Kupffer and endothelial cells lacked several glutathione S-transferase isoenzymes present in parenchymal cells. At 5 days after administration of Arocolor 1254 glutathione S-transferase activity was only enhanced in parenchymal cells; furthermore, selenium-dependent glutathione peroxidase activity decreased in parenchymal and non-parenchymal cells. At 13 days after a single injection of Aroclor 1254 a strong induction of glutathione S-transferase had taken place in all three cell types, whereas selenium-dependent glutathione peroxidase activity remained unchanged (endothelial cells) or was depressed (parenchymal and Kupffer cells). Hence these results clearly establish that glutathione S-transferase and glutathione peroxidase are differentially regulated in rat liver parenchymal as well as non-parenchymal cells. The presence of glutathione peroxidase and several glutathione S-transferase isoenzymes capable of detoxifying a variety of compounds in Kupffer and endothelial cells might be crucial to protect the liver from damage by potentially hepatotoxic substances.


2005 ◽  
Vol 9 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Mohamed A. El-far ◽  
Mohamed A. Bakr ◽  
Sami E. Farahat ◽  
Elsaid A. Abd El-Fattah

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