Glutathione peroxidase activity in selenium-deficient rat liver☆
23 Aug 1976-Biochemical and Biophysical Research Communications (Biochem Biophys Res Commun)-Vol. 71, Iss: 4, pp 952-958
TL;DR: Two peaks of glutathione peroxidase activity were present in the Sephadex G-150 gel filtration chromatogram of rat liver supernatant when 1.5 mM cumene hydroperoxide was used as substrate, and the second peak represents a second glutathienase activity which catalyzes the destruction of organic hydroperoxides but has little activity toward H 2 O 2 and which persists in severe selenium deficiency.
Abstract: Glutathione peroxidase activity in the liver supernatant from rats fed a Se-deficient diet for 2 weeks was 8% of control when measured with H 2 O 2 but 42% of control when assayed with cumene hydroperoxide. Two peaks of glutathione peroxidase activity were present in the Sephadex G-150 gel filtration chromatogram of rat liver supernatant when 1.5 mM cumene hydroperoxide was used as substrate. Only the first peak was detected when 0.25 mM H 2 O 2 was used as substrate. The first peak was absent from chromatograms of Se-deficient rat liver supernatants; but the second peak, which eluted at a position corresponding to M.W. = 39,000, appeared unchanged. The second peak thus represents a second glutathione peroxidase activity which catalyzes the destruction of organic hydroperoxides but has little activity toward H 2 O 2 and which persists in severe selenium deficiency.
Citations
More filters
TL;DR: This chapter presents a procedure for the preparation of glutathione peroxidase, which is regarded as a major protective system against endogenously and exogenously induced lipid peroxidation.
Abstract: Publisher Summary This chapter presents a procedure for the preparation of glutathione peroxidase, which is regarded as a major protective system against endogenously and exogenously induced lipid peroxidation. Two types of methods are used for determining the activity of glutathione peroxidase. One involves a direct measurement of unconsumed glutathione (GSH) at fixed time periods by polarographic GSH analysis' (Method 1), or by the dithionitrobenzoic acid method (Method 2). The second approach takes advantage of the capability of glutathione reductase, with nicotinamide adenine dinucleotide phosphate (NADPH), to regenerate GSH from oxidized GSH. The decrease in NADPH is continuously measured spectrophotometrically, while the GSH concentration in the enzymatic cycle remains essentially constant (Method 3). A convenient source for the preparation of glutathione peroxidase is bovine blood including the following steps: hemolysate; organic solvent precipitation; phosphate precipitation; absorption to phenyl-sepharose; and washing on diethylaminoethyl (DEAE)–sephadex, S-300 sephacryl, and hydroxylapatite column.
2,809 citations
TL;DR: The existing evidence support the view that oxidative stress may play a crucial role in cardiac and vascular abnormalities in different types of cardiovascular diseases and that the antioxidant therapy may prove beneficial in combating these problems.
Abstract: ObjectivesIn view of the critical role of intracellular Ca2+-overload in the genesis of myocyte dysfunction and the ability of reactive oxygen species (ROS) to induce the intracellular Ca2+-overload, this article is concerned with analysis of the existing literature with respect to the role of oxida
1,394 citations
TL;DR: Current evidence in clinical research does not show unequivocal distinction between causal or associative relationships of pro-oxidants to the disease process.
Abstract: The occurrence of reactive oxygen species, known as pro-oxidants, is an attribute of normal aerobic life The steady-state formation of pro-oxidants is balanced by a similar rate of their consumption by antioxidants that are enzymatic and/or nonenzymatic "Oxidative stress" results from imbalance in this pro-oxidant-antioxidant equilibrium in favor of the pro-oxidants A number of diseases are associated with oxidative stress, being the basis of antioxidant therapy Current evidence in clinical research does not show unequivocal distinction between causal or associative relationships of pro-oxidants to the disease process
1,224 citations
TL;DR: Diverse biological processes such as inflammation, carcinogenesis, ageing, radiation damage and photobiological effects appear to involve reactive oxygen species, and oxidative stress denotes a shift in the prooxidant/antioxidant balance in favor of the former.
Abstract: As a normal attribute of aerobic life, structural damage to organic compounds of a wide variety (DNA, proteins, carbohydrates and lipids) may occur as a consequence of oxidative reactions. Oxidative damage inflicted by reactive oxygen species has been called “oxidative stress”. Biological systems contain powerful enzymatic and nonenzymatic antioxidant systems, and oxidative stress denotes a shift in the prooxidant/antioxidant balance in favor of the former. Diverse biological processes such as inflammation, carcinogenesis, ageing, radiation damage and photobiological effects appear to involve reactive oxygen species. This field of research provides new perspectives in biochemical pharmacology, toxicology, radiation biochemistry as well as pathophysiology.
1,179 citations
TL;DR: The present results indicate that a knock-out of GSHPx may be adequately compensated under nonstressed conditions, but that after administration of mitochondrial toxins GSHpx plays an important role in detoxifying increases in oxygen radicals.
Abstract: Glutathione peroxidase (GSHPx) is a critical intracellular enzyme involved in detoxification of hydrogen peroxide (H 2 O 2 ) to water. In the present study we examined the susceptibility of mice with a disruption of the glutathione peroxidase gene to the neurotoxic effects of malonate, 3-nitropropionic acid (3-NP), and 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP). Glutathione peroxidase knock-out mice showed no evidence of neuropathological or behavioral abnormalities at 2–3 months of age. Intrastriatal injections of malonate resulted in a significant twofold increase in lesion volume in homozygote GSHPx knock-out mice as compared to both heterozygote GSHPx knock-out and wild-type control mice. Malonate-induced increases in conversion of salicylate to 2,3- and 2,5-dihydroxybenzoic acid, an index of hydroxyl radical generation, were greater in homozygote GSHPx knock-out mice as compared with both heterozygote GSHPx knock-out and wild-type control mice. Administration of MPTP resulted in significantly greater depletions of dopamine, 3,4-dihydroxybenzoic acid, and homovanillic acid in GSHPx knock-out mice than those seen in wild-type control mice. Striatal 3-nitrotyrosine (3-NT) concentrations after MPTP were significantly increased in GSHPx knock-out mice as compared with wild-type control mice. Systemic 3-NP administration resulted in significantly greater striatal damage and increases in 3-NT in GSHPx knock-out mice as compared to wild-type control mice. The present results indicate that a knock-out of GSHPx may be adequately compensated under nonstressed conditions, but that after administration of mitochondrial toxins GSHPx plays an important role in detoxifying increases in oxygen radicals.
1,129 citations
Cites methods from "Glutathione peroxidase activity in ..."
...These mice show an 85% reduction in cortex GSHPx activity from 0.155 6 0.021 to 0.024 6 0.017, p , 0.001 as previously described (Lawrence and Burk, 1976)....
[...]
References
More filters
Journal Article•
TL;DR: Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
Abstract: Since 1922 when Wu proposed the use of the Folin phenol reagent for the measurement of proteins, a number of modified analytical procedures utilizing this reagent have been reported for the determination of proteins in serum, in antigen-antibody precipitates, and in insulin. Although the reagent would seem to be recommended by its great sensitivity and the simplicity of procedure possible with its use, it has not found great favor for general biochemical purposes. In the belief that this reagent, nevertheless, has considerable merit for certain application, but that its peculiarities and limitations need to be understood for its fullest exploitation, it has been studied with regard to effects of variations in pH, time of reaction, and concentration of reactants, permissible levels of reagents commonly used in handling proteins, and interfering substances. Procedures are described for measuring protein in solution or after precipitation with acids or other agents, and for the determination of as little as 0.2 gamma of protein.
289,852 citations
TL;DR: Glutathione peroxidase activity is found to be associated with a relatively stable, nondialyzable, heat-labile, intracellular component which is separable from hemoglobin, by gel filtration and ammonium sulfate precipitation.
Abstract: An assay procedure is described in which blood cell glutathione peroxidase may be accurately measured by a direct spectrophotometric procedure. Glutathione peroxidase activity is found to be associated with a relatively stable, nondialyzable, heat-labile, intracellular component which is separable from hemoglobin, by gel filtration and ammonium sulfate precipitation. The activity appears to be dependent upon active sulfhydryl groups and is unaffected by low concentrations of azide, cyanide, or ferricyanide.
10,439 citations
TL;DR: When hemolyzates from erythrocytes of selenium-deficient rats were incubated in vitro in the presence of ascorbate or H2O2, added glutathione failed to protect the hemoglobin from oxidative damage.
Abstract: When hemolyzates from erythrocytes of selenium-deficient rats were incubated in vitro in the presence of ascorbate or H(2)O(2), added glutathione failed to protect the hemoglobin from oxidative damage. This occurred because the erythrocytes were practically devoid of glutathione-peroxidase activity. Extensively purified preparations of glutathione peroxidase contained a large part of the (75)Se of erythrocytes labeled in vivo. Many of the nutritional effects of selenium can be explained by its role in glutathione peroxidase.
6,893 citations
TL;DR: The aulh,o~s described an incorpora t ion o f in t raper imne~ ly injee~ted '~s Se in to a IVrOtein f ract ion w N e h after partial puMfieafion showed GSH peroxidase a ctiVi:ty.
Abstract: Se]enk~m waz discovered as ~n essential trace e lement fo~ mammah; by Schwa,~z and ,'5\"lotz I3] hn 1957. The ~alhol,0gical symptoln~ o f ~elerfium d e f i e ~ r e n e y elosely ~esemble those seen in 'iocophe~ol d.eficient animals, In a d d h i o n , growith dep,~esfion, increased mor ta l i ly , myopa tNe~ and decreased fel t i l i~ , developed in ~oeoph~ol deficiency .could be hnp~oved by applicat ion ..of dietary ~ l . enNm I43, T h e v n e r N s t i : effe~:~s o f die tary ~ele~ium rand locophe~N suggest a c o m m o n physiologic.a] N~get ,of these ~wo e.ompounds. The Noehem~eal mechan i sm by 'which selenium ac l sa s ,an an t iox idant ~em'ained ohscare ~n~fl R o t m e k and o~wo,lke~s I5] pre~emed some expeI~mema] or]donee fo~ the. involvement o f se]enium in ~_he GSH-dependem me ,abo l i sm ~ f hyd~,operoxide~. ,The aulh,o~s described an incorpora t ion o f in t raper imne~ ly injee~ted '~s Se in to a IVrOtein f ract ion w N e h after partial puMfieafion showed GSH peroxidase a ctiVi:ty.I t was assumed ,IhaI selen-~m m~ght fun,~fion as a cons t i tuent uf,G~3tt pero:ddase. In ruder ~a~ cheek this hypot~hesis wa de te i rn ined the s~lenNm e,on.,tent .of ,GSH pe~,oxidase isolaled in \" \" h:omageneou~ and , .c~taI!ine s~ate f r o m bo'cine b lood by neu~,ron aeries 'don analysis. We a c I ~ y f o u n d ,four 2, ]..Preparation a f GSH pe~oxid~s.e
1,252 citations
TL;DR: The results suggest that tissue GSH-Px can be used as an indicator of animal Se status, but other factors such as age, sex, and dietary vitamin E may have to be considered.
Abstract: Experiments were conducted with male rats to quantitate the relation ship between dietary selenium (Se) intake and the amount of the enzyme glutathione peroxidase (GSH-Px) in erythrocytes and liver. Weanling male rats were fed torula yeast-based diets with 0, 0.05, 0.1, 0.5, 1.0, or 5.0 ppm Se supplemented as sodium selenite. Liver GSH-Px fell to undetectable levels (<1% of that found in the weanling rats) within 24 days in the O ppm Se group; feeding 0.1 ppm Se, or greater, caused liver GSH-Px to increase above that found in the weanling rats. The erythrocyte GSH-Px response to lack of dietary Se was somewhat smaller in magnitude and more gradual; however, only 21% of initial erythrocyte GSH-Px activity remained in the unsupplemented group after 66 days. Increased dietary Se resulted in corresponding increases of erythrocyte GSH-Px activity. Resupplementing with 0.1, 0.5, or 5.0 ppm Se elevated the depressed erythrocyte GSH-Px levels of the deficient rats. Increased dietary Se provided for both faster elevation, and higher maximal GSH-Px activity which in all cases was achieved 60 to 90 days after resupplementation. The results suggest that tissue GSH-Px can be used as an indicator of animal Se status, but other factors such as age, sex, and dietary vitamin E may have to be considered. Lack of GSH-Px in livers of Se-deficient rats may explain the liver necrosis observed when the diet is also deficient in vitamin E and sulfur-containing amino acids. J. Nutr. 104: 580-587,
1,103 citations