The true oxidized glutathione content of red blood cells obtained by new enzymic and paper chromatographic methods

Güntherberg, H.; J, Rost

doi:10.1016/0003-2697(66)90025-x

Cited by 89 publications

(30 citation statements)

References 9 publications

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“…We have found that mouse glutathione reductase retained 70 % of its activity upon preincubation with 50 yM NADPH in the presence of 50 yM GSSG and 1 mM GSH; conditions which mimic the physiological GSSG/GSH ratio [59,60]. However, a lower concentration of GSSG than NADPH would produce a more pronounced inactivation.…”

Section: Properties Of the Inactive Enzymementioning

confidence: 92%

Mouse‐Liver Glutathione Reductase

López-Barea

Lee

1979

European Journal of Biochemistry

110

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Glutathione reductase from the liver of DBA/2J mice was purified to homogeneity by means of ammonium sulfate fractionation and two subsequent affinity chromatography steps using 8-(6-aminohexyl)-amino-2'-phospho-adenosine diphosphoribose and N6-(6-aminohexyl)-adenosine 2', 5'-bisphosphate-Sepharose columns. A facile procedure for the synthesis of 8-(6-aminohexyl)-amino-2'-phospho-adenosine diphosphoribose is also presented. The purified enzyme exhibits a specific activity of 158 U/mg and an A280/A460 of 6.8. It was shown to be a dimer of M , 105000 with a Stokes radius of 4.18 nm and an isoelectric point of 6.46. Amino acid composition revealed some similarity between the mouse and the human enzyme. Antibodies against mouse glutathione reductase were raised in rabbits and exhibited high specificity. The catalytic properties of mouse liver glutathione reductase have been studied under a variety of experimental conditions. As with the same enzyme from other sources, the kinetic data are consistent with a 'branched' mechanism.The enzyme was stabilized against thermal inactivation at 80°C by GSSG and less markedly by NADP' and GSH, but not by NADPH or FAD. Incubation of mouse glutathione reductase in the presence of NADPH or NADH, but not NADP' or NAD', produced an almost complete inactivation. The inactivation by NADPH was time, pH and concentration dependent. Oxidized glutathione protected the enzyme against inactivation, which could also be reversed by GSSG or other electron acceptors. The enzyme remained in the inactive state even after eliminating the excess NADPH. The inactive enzyme showed the same molecular weight as the active glutathione reductase. The spectral properties of the inactive enzyme have also been studied. It is proposed that auto-inactivation of glutathione reductase by NADPH and the protection as well as reactivation by GSSG play in vivo an important regulatory role.

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Section: Properties Of the Inactive Enzymementioning

confidence: 92%

Mouse‐Liver Glutathione Reductase

López-Barea

Lee

1979

European Journal of Biochemistry

110

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“…29,30 The thiol index (GSH/GSSG), the ratio of reduced to oxidated glutathione, was measured using a colorimetric assay (GSH/GSSG-412 BIOXYTECH) described by Gunthenberg. 31 …”

Section: Methodsmentioning

confidence: 99%

Role of the nitric oxide metabolic pathway and prostanoids in the pathogenesis of endothelial dysfunction and essential hypertension in young men

2010

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The aim of this study was to explore the role of selected prostanoids and the nitric oxide (NO) metabolic pathway in the pathogenesis of endothelial dysfunction (ED) in young men with and without essential hypertension (HTN). A total of 70 men aged 18-40 years old (23 hypertensive and 47 normotensive) were investigated. Initial metabolite concentrations of the NO pathway (asymmetric dimethylarginine, L-arginine and symmetric dimethylarginine), selected cardiovascular risk markers (serum lipids, creatinine, glucose and high-sensitivity C-reactive protein), oxidative stress markers (malonylodialdehyde, thiol index and nitrotyrosine) and prostanoids (thromboxane B2 (TxB 2 ) and 6-keto-prostaglandin F (PGF)-1-a) were measured. Ultrasound assessment of endothelial function (flow-mediated vasodilation (FMD)) of the brachial artery was studied before and after intravenous infusion of L-arginine (16.0 g). All measurements were repeated after oral administration of indomethacin (75 mg per day) for 2 days. The prevalence of ED was similar in both hypertensive and normotensive groups. A lower baseline plasma level of 6-keto-PGF-1-a and a higher baseline of TxB 2 were observed in the hypertensive group. A different response to indomethacin assessed by prostanoid levels was observed and was dependent on the presence of HTN. No significant differences in metabolites of the NO pathway were observed at either baseline or following indomethacin treatment. In hypertensive patients, L-arginine and indomethacin had a synergistic positive effect on FMD. ED in young normotensive men primarily depends on NO deficiency. In young hypertensive men, disorders in prostanoid metabolism have important roles in decreasing NO bioavailability. The high prevalence of ED in potentially healthy subjects suggests that the ultrasound FMD measurement is an important tool in the stratification of cardiovascular risk.

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“…Specifically, reduced GSH to oxidized GSH ratio decreases under oxidative conditions. Quite a number of assays including that of Guntherberg andRost (1966), andGriffith (1980) are utilized to measure the GSH levels in biological tissues.…”

Section: Measurement Of Non-enzymatic Antioxidantsmentioning

confidence: 99%

Review: In vivo and postmortem effects of feed antioxidants in livestock: a review of the implications on authorization of antioxidant feed additives

Salami

Guinguina

Agboola

et al. 2016

Animal

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The pivotal roles of regulatory jurisdictions in the feed additive sector cannot be over-emphasized. In the European Union (EU), antioxidant substances are authorized as feed additives for prolonging the shelf life of feedstuffs based on their effect for preventing lipid peroxidation. However, the efficacy of antioxidants transcends their functional use as technological additives in animal feeds. Promising research results have revealed the in vivo efficacy of dietary antioxidants for combating oxidative stress in production animals. The in vivo effect of antioxidants is significant for enhancing animal health and welfare. Similarly, postmortem effect of dietary antioxidants has been demonstrated to improve the nutritional, organoleptic and shelf-life qualities of animal products. In practice, dietary antioxidants have been traditionally used by farmers for these benefits in livestock production. However, some antioxidants particularly when supplemented in excess could act as prooxidants and exert detrimental effects on animal well-being and product quality. Presently, there is no exclusive legislation in the EU to justify the authorization of antioxidant products for these in vivo and postmortem efficacy claims. To indicate these efficacy claims and appropriate dosage on product labels, it is important to broaden the authorization status of antioxidants through the appraisal of existing EU legislations on feed additives. Such regulatory review will have major impact on the legislative categorization of antioxidants and the efficacy assessment in the technical dossier application. The present review harnesses the scientific investigations of these efficacy claims in production animals and, proposes potential categorization and appraisal of in vivo methodologies for efficacy assessment of antioxidants. This review further elucidates the implication of such regulatory review on the practical application of antioxidants as feed additives in livestock production. Effecting these regulatory changes will stimulate the innovation of more potent antioxidant products and create potential new markets that will have profound economic impacts on the feed additive industry. Based on the in vivo efficacy claims, antioxidants may have to contend with the legislative controversy of either to be considered as veterinary drugs or feed additives. In this scenario, antioxidants are not intended to diagnose or cure diseases as ascribed to veterinary products. This twisted distinction can be logically debated with reference to the stipulated status of feed additives in Commission Regulation (EC) No 1831/2003. Nonetheless, it is imperative for relevant stakeholders in the feed additive industry to lobby for the review of existing EU legislations for authorization of antioxidants for these efficacy claims.

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The true oxidized glutathione content of red blood cells obtained by new enzymic and paper chromatographic methods

Cited by 89 publications

References 9 publications

Mouse‐Liver Glutathione Reductase

Mouse‐Liver Glutathione Reductase

Role of the nitric oxide metabolic pathway and prostanoids in the pathogenesis of endothelial dysfunction and essential hypertension in young men

Review: In vivo and postmortem effects of feed antioxidants in livestock: a review of the implications on authorization of antioxidant feed additives

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