Pyrimidine nucleotides impair phosphoribosylpyrophosphate (PRPP) synthetase subunit aggregation by sequestering magnesium. A mechanism for the decreased PRPP synthetase activity in hereditary erythrocyte pyrimidine 5'-nucleotidase deficiency

The activity of phosphoribosylpyrophosphate (PRPP) synthetase (ATP: D-ribose-5-phosphate pyrophosphotransferase, EC 2.7.6.1) is decreased in the erythrocyte in hereditary pyrimidine 5'-nucleotidase (P5N) deficiency. Given the increased pyrimidine nucleotide content of the P5N-deficient erythrocyte, we evaluated the effects of prototypic pyrimidine nucleotides on the activity of PRPP synthetase. In normal hemolysate a 1.0 mM combination of cytidine tri-, di- and monophosphate (CTP/CDP/CMP) inhibited PRPP synthetase activity and changed the ribose 5-phosphate (R5P) saturation curve from a hyperbola to a biphasic shape. Untreated crude hemolysate from P5N-deficient erythrocytes showed a biphasic R5P kinetic curve. Since the activity of PRPP synthetase is dependent on its state of subunit aggregation, we examined PRPP synthetase subunit aggregation using gel permeation chromatography. P5N-deficient erythrocytes had a decreased absolute amount of aggregated PRPP synthetase and almost a total loss of disaggregated PRPP synthetase. Using normal hemolysate, 1 mM CTP/CDP/CMP interfered with the ability of 1.0 mM ATP and 2.0 mM MgCl2 to promote PRPP synthetase subunit aggregation. Increasing the MgCl2 to 6.0 mM overcame the inhibitory effect of CTP/CDP/CMP. Thus, the decreased PRPP synthetase activity of the P5N-deficient erythrocyte is due, at least in part, to the ability of the accumulated pyrimidine nucleotides to sequester magnesium and to interfere with the subunit aggregation of PRPP synthetase.     

Pyrimidine nucleotides impair phosphoribosylpyrophosphate (PRPP) synthetase subunit aggregation by sequestering magnesium. A mechanism for the decreased PRPP synthetase activity in hereditary erythrocyte pyrimidine 5′-nucleotidase deficiency

The activity of phosphoribosylpyrophosphate (PRPP) synthetase (ATP:d-ribose-5-phosphate pyrophosphotransferase, EC 2.7.6.1) is decreased in the erythrocyte in hereditary pyrimidine 5′-nucleotidase (P5N) deficiency. Given the increased pyrimidine nucleotide content of the P5N-deficient erythrocyte, we evaluated the effects of prototypic pyrimidine nucleotides on the activity of PRPP synthetase. In normal hemolysate a 1.0 mM combination of cytidine tri-, di-, and monophosphate (CTP/CDP/CMP) inhibited PRPP synthetase activity and changed the ribose 5-phosphate (R5P) saturation curve from a hyperbola to a biphasic shape. Untreated crude hemolysate from P5N-deficient erythrocytes showed a biphasic R5P kinetic curve. Since the activity of PRPP synthetase is dependent on its state of subunit aggregation, we examined PRPP synthetase subunit aggregation using gel permeation chromatography. P5N-deficient erythrocytes had a decreased absolute amount of aggregated PRPP synthetase and almost a total loss of disaggregated PRPP synthetase. Using normal hemolysate, 1 mM CTP/CDP/CMP interfered with the ability of 1.0 mM ATP and 2.0 mM MgCl₂ to promote PRPP synthetase subunit aggregation. Increasing the MgCl₂ to 6.0 mM overcame the inhibitory effect of CTP/CDP/CMP. Thus, the decreased PRPP synthetase activity of the P5N-deficient erythrocyte is due, at least in part, to the ability of the accumulated pyrimidine nucleotides to sequester magnesium and to interfere with the subunit aggregation of PRPP synthetase.     

Some aspects of glutathione metabolism in ataxia-telangiectasia fibroblasts

Levels of glutathione (GSH) and two enzymes involved in GSH metabolism, glutathione reductase (GR) and glutathione-S-transferase(s) (GST), were measured in four SV40-transformed human fibroblast cell lines. MRC5-V1 and GM0637, derived from normal individuals, had mean GSH levels of 4.2 and 6.5 nmoles/10(6) cells, respectively. TAT2SF and AT5BIVA, both from ataxia-telangiectasia (A-T) patients, respectively had 6.5 and 4.2 nmol/10(6) cells, indicating that basal GSH levels were similar in A-T and normal cells. There was some variation in GST activity among the four cell lines but deficiency in this enzyme cannot be associated with radiosensitivity in A-T. When GR activity was measured, A-T cells had approximately 82 per cent of the mean normal activity. Though statistically significant, (P = 0.05), this small deficiency could be due to chance and is unlikely to be responsible for the radiosensitive phenotype of A-T.     

Glutathione and its associated enzymes in peripheral blood cells in different stages of chronic renal insufficiency

Summary Reduced glutathione (GSH) levels and glutathione reductase (GR) and glutathione S-transferase (GST) activities were investigated in the erythrocytes and lymphocytes of non-dialyzed patients with varying degrees of chronic renal insufficiency, and also of patients on regular hemodialysis treatment. GSH, GR and GST levels were higher in erythrocytes and lymphocytes of examined patients as compared to their corresponding age-matched healthy controls. A correlation was found between the degree of renal insufficiency and the above parameters tested. A routine hemodialysis did not significantly affect erythrocyte and lymphocyte GSH content and activities of its associated enzymes. The increased GSH levels as well as GSH-linked enzyme activities of blood cells in uremia may be a protective mechanism for the cells due to the accumulation of toxic, oxidizing, wastes in the blood as a result of the uremic state. This view is supported by the results ofin vitro experiments, which have shown that GR and GST activities of normal human lymphocytes are increased when incubated with plasma from uremic patients.     

CDP-choline does not inhibit erythrocyte glycolytic or pentose phosphate pathway enzyme activity

An increased concentration of cytidine diphosphocholine (CDP-choline) has been observed in erythrocytes in the hemolytic anemia due to hereditary pyrimidine 5'-nucleotidase deficiency (P5Nase, EC 3.1.3.5) and in a patient with a chronic hemolytic anemia not due to P5Nase deficiency, as reported by Paglia and co-workers in 1983. In the current studies, we were unable to demosntrate a significant inhibitory effect of 4 mmol/l CDP-choline on the activities of the enzymes of the Embden-Meyerhof and pentose phosphate pathways. The physiologic significance of increased erythrocytic CDP-choline remains to be determined.     

Relationship between cell age, glutathione and cation concentrations in sheep erythrocytes with a normal and a defective transport system for amino acids

Percoll density gradients were used to separate sheep erythrocytes according to cell age. Erythrocytes with low intracellular levels of glutathione (GSH) caused by an inherited deficiency of the System C amino acid transporter exhibited large age-related decreases in GSH and K+ content. In contrast, there was no age-related loss of intracellular GSH in normal sheep erythrocytes or in sheep erythrocytes with low GSH resulting from a diminished activity of gamma-glutamylcysteine synthetase. Loss of GSH from amino acid transport-deficient erythrocytes was paralleled by the progressive appearance of Heinz bodies in the cells, indicating an increased susceptibility to oxidative damage.     

Relationship between cell age,glutathione and cation concentrations in sheep erythrocytes with a normal and defective transport system for amino acids

Percoll density gradients were used to separate sheep erythrocytes according to cell age. Erythrocytes with low intracellular levels of glutathione (GSH) caused by an inherited deficiency of the System C amino acid transporter exhibited large age-realted decreases in GSH and K⁺ content. In contrast, there was no age-related loss of intracellular GSH in normal sheep erythrocytes or in sheep erythrocytes with low GSH resulting from a diminished activity of γ-glutamylcysteine synthetase. Loss of GSH from amino acid transport-deficient erythrocytes was parallel by the progressive appearance of Heinz bodies in the cells, indicating an increased susceptibility to oxidative damage.     

L-Cysteine influx in type 2 diabetic erythrocytes

Erythrocyte oxidative stress has been implicated in the pathogenesis of diabetes mellitus, and the deficiency of antioxidant defense by the glutathione (GSH) pathway is thought to be one of the factors responsible for development of complications in diabetes. Erythrocytes require L-cysteine for the synthesis of GSH and the rate of synthesis is determined only by L-cysteine availability. In the present study we have found that the L-cysteine influx in erythrocytes from type 2 diabetic patients was significantly lower compared to age-matched controls. The decreased influx may be one of the factors leading to low GSH concentration observed in type 2 diabetes. Since L-cysteine is the limiting amino acid in GSH synthesis, any strategy aimed to increase L-cysteine influx in erythrocytes may be beneficial for type 2 diabetic patients.     

Altered purine and pyrimidine metabolism in erythrocytes with purine nucleoside phosphorylase deficiency

Purine and pyrimidine metabolism was compared in erythrocytes from three patients from two families with purine nucleoside phosphorylase deficiency and T-cell immunodeficiency, one heterozygote subject for this enzyme deficiency, one patient with a complete deficiency of hypoxanthine-guanine phosphoribosyltransferase, and two normal subjects. The erythrocytes from the heterozygote subject were indistinguishable from the normal erythrocytes. The purine nucleoside phosphorylase deficient erythrocytes had a block in the conversion of inosine to hypoxanthine. The erythrocytes with 0.07% of normal purine nucleoside phosphorylase activity resembled erythrocytes with hypoxanthine-guanine phosphoribosyltransferase deficiency by having an elevated intracellular concentration of PP-ribose-P, increased synthesis of PP-ribose-P, and an elevated rate of carbon dioxide release from orotic acid during its conversion to UMP. Two hypotheses to account for the associated immunodeficiency—that the enzyme deficiency leads to a block of PP-ribose-P synthesis or inhibition of pyrimidine synthesis—could not be supported by observations in erythrocytes from both enzyme-deficient families.This work was supported by U.S. Public Health Service Grant AM 19674 and 5 M01 RR 42 and by a Grant-In-Aid from American Heart Association (77-849) and with funds contributed in part by the Michigan Heart Association. N.L.E. is a Rheumatology Fellow from the Rackman Arthritis Research Unit supported by Training Grant USPHS AM 07080.     

The secondary structure of nucleotidyl-(5' bound to N)-amino acids containing different heterocyclic bases and amino acids]

Nucleotidyl-(5' leads to N)-amino acids containing different heterocycle bases: adenine, guanine, hypoxanthine, cytosine, uracyl, and aromatic amino acids: phenylalanine, tyrosine and tryptophan, have been investigated by proton magnetic resonance and circular dichroism. For all the compounds studied folded conformation have been shown stabilized by hydrophobic interaction in aqueous solution. The comparison of the results of the studied nucleotidyl-(5' leads to N)-amino acids unable us to build four secondary structure types in these very compounds. Phenylalanine and tyrosine derivatives of purine nucleotides can be regarded as the first type, tryptophan derivatives of purine nucleotides as the second type, phenylalanine and tyrosine derivatives of pyrimidine nucleotides as the third type and tryptophan derivatives of pyrimidine nucleotides as the fourth type. For each group of these compounds conformational models have been built. In all these compounds the anti-conformation has been proved to exist.     

2,4,5-T and 2,4,5-TCP induce oxidative damage in human erythrocytes: the role of glutathione

The molecular basis of the toxic properties of phenoxy herbicides in humans and animals has been insufficiently studied. In this study, damage parameters [levels of reduced glutathione (GSH) and total glutathione; activity of glutathione reductase (GR); activities of catalase (CAT) and superoxide dismutase (SOD); levels of adenine nucleotides and adenine energy charge (AEC)] were measured in human erythrocytes exposed in vitro to 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and its metabolite 2,4,5-trichlorophenol (2,4,5-TCP). Both 2,4,5-T and 2,4,5-TCP decreased the level of reduced glutathione (GSH) in erythrocytes in comparison to the control, but did not significantly change the total glutathione (2GSH + GSSG). This suggests that GSH concentration decreases concomitantly with an increase in oxidized glutathione (GSSG). 2,4,5-TCP at 100 ppm significantly decreased catalase and SOD activities. 2,4,5-T and 2,4,5-TCP did not significantly change the activity of glutathione reductase. 2,4,5-TCP decreased the level of ATP and increased the content of ADP and AMP, indicating a fall in AEC. 2,4,5-T and 2,4,5-TCP significantly changed the erythrocyte morphology. All these data are evidence of oxidative stress in erythrocytes incubated with 2,4,5-T and 2,4,5-TCP; the stress appears to be more intense in the case of 2,4,5-TCP.     

Increased efflux of oxidized glutathione (GSSG) causes glutathione depletion and potentially diminishes antioxidant defense in sickle erythrocytes

Erythrocytes are both an important source and target of reactive oxygen species in sickle cell disease. Levels of glutathione, a major antioxidant, have been shown to be decreased in sickle erythrocytes and the mechanism leading to this deficiency is not known yet. Detoxification of reactive oxygen species involves the oxidation of reduced glutathione (GSH) into glutathione-disulfide (GSSG) which is actively transported out of erythrocyte. We questioned whether under oxidative conditions, GSSG efflux is increased in sickle erythrocytes. Erythrocytes of 18 homozygous sickle cell patients and 9 race-matched healthy controls were treated with 2,3-dimethoxy-l,4-naphthoquinone, which induces intracellular reactive oxygen species generation, to stimulate GSSG production. Intra- and extracellular concentrations of GSH and GSSG were measured at baseline and during 210-minute 2,3-dimethoxy-l,4-naphthoquinone stimulation. While comparable at baseline, intracellular and extracellular GSSG concentrations were significantly higher in sickle erythrocytes than in healthy erythrocyte after 210-minute 2,3-dimethoxy-l,4-naphthoquinone stimulation (69.9 ± 3.7 μmol/l vs. 40.6 ± 6.9 μmol/l and 25.8 ± 2.7 μmol/l vs. 13.6 ± 1.7 μmol/l respectively, P<0.002). In contrast to control erythrocytes, where GSH concentrations remained unchanged (176 ± 8.4 μmol/l vs. 163 ± 13.6 μmol/l, NS), GSH in sickle erythrocytes decreased significantly (from 167 ± 8.8 μmol/l to 111 ± 11.8 μmol/l, P<0.01) after 210-minute 2,3-dimethoxy-l,4-naphthoquinone stimulation. Adding multidrug resistance-associated protein-1 inhibitor (MK571) to erythrocytes blocked GSSG efflux in both sickle and normal erythrocytes. GSSG efflux, mediated by multidrug resistance-associated protein-1, is increased in sickle erythrocytes, resulting in net loss of intracellular glutathione and possibly higher susceptibility to oxidative stress.     

Niacin deficiency causes oxidative stress in rat bone marrow cells but not through decreased NADPH or glutathione status

Niacin (vitamin B(3)), in the form of NADPH, is required for the regeneration of glutathione (GSH), which is the substrate of GSH peroxidase. In this study, we examined the effect of dietary niacin deficiency on protein and DNA oxidation in bone marrow cells of Long-Evans rats. Western blotting was used to measure 2,4-dinitrophenylhydrazine-reactive protein carbonyl products, and the Biotrin OxyDNA method was used to measure 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). The levels of both protein carbonyls and 8-oxodG were increased by 50% in niacin-deficient bone marrow cells. To examine whether this oxidant damage involves altered metabolism of pyridine nucleotides and glutathione, both oxidized and reduced forms of pyridine nucleotides (NAD(+), NADH, NADP(+), NADPH) and glutathione (GSSG and GSH) were quantified in total and nucleated bone marrow cells. NAD and NADP(+) levels were decreased 80% and 22%, respectively, by niacin deficiency. NADPH and GSH were not depleted by niacin deficiency, showing that oxidant injury was not due directly to impairment of this pathway. Oxidative stress, of uncertain etiology, may play a role in the observed genomic instability and sensitivity to leukemogenesis in bone marrow cells during niacin deficiency.     

The antioxidant status during maturation of reticulocytes to erythrocytes in type 2 diabetics

Free radical-induced lipid peroxidation has been associated with numerous disease processes including diabetes mellitus. The extent of lipid peroxidation (LPO) and antioxidant defense system [i.e., levels of glutathione (GSH), glucose-6-phosphate dehydrogenase (G6PDH), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase (CAT)] were evaluated in reticulocytes and erythrocytes of type 2 diabetic males and age-matched controls. Type 2 diabetics have shown increased lipid peroxidation and decreased levels of GSH, GR, GPx, G6PDH, and GST both in reticulocytes and erythrocytes compared to controls, indicating the presence of oxidative stress and defective antioxidant systems in these patients. CAT activity is found to be enhanced in both the reticulocytes and erythrocytes of diabetics, with a greater percentage enhancement in reticulocytes. The extent of increase in lipid peroxidation is greater in erythrocytes compared to reticulocytes in these patients. Furthermore, the maturation of reticulocytes to erythrocytes resulted in decreased GSH and decreased activities of all antioxidant enzymes (except CAT) both in normals and type 2 diabetes individuals, indicating decreased scavenging capacity as reticulocytes mature to erythrocytes. These maturational alterations are further intensified in type 2 diabetics. The present study reveals that the alterations in lipid peroxidation and antioxidant system lean toward early senescence of erythrocytes in type 2 diabetic patients.     

Determination of reduced and oxidized glutathione in erythrocytes by high-performance liquid chromatography with ultraviolet absorbance detection

A method is described for simultaneous quantitation of reduced (GSH) and oxidized (GSSG) glutathione in erythrocytes by HPLC. They were determined by standard addition method. Blood samples were collected in tubes containing 1,10-phenanthroline. The separated erythrocytes were hemolyzed with water containing standard. After deproteinization, GSH and GSSG were converted to N-(2,4-dinitrophenyl) derivatives and analyzed by HPLC with UV detection. The coefficients of variation of GSH and GSSG on replicate assays were 6% and 8%, respectively. The stabilities of GSH and GSSG and of the derivatives were also examined. The present method appears to be satisfactory for determination of these physiological concentrations in erythrocytes.     

Comparative effects of mono-, di-, tri-, and tetrasulfides derived from plants of the Allium family: redox cycling in vitro and hemolytic activity and Phase 2 enzyme induction in vivo

Epidemiological evidence indicates that a high dietary intake of plants of the Allium family, such as garlic and onions, decreases the risk of cancer in humans. It has been suggested that this effect is due to the ability of the aliphatic mono-, di-, tri-, and tetrasulfides derived from these vegetables to increase tissue activities of Phase 2 detoxification enzymes. In contrast, toxic effects have been recorded in domestic and farm animals after the consumption of garlic or onions, involving oxidative damage to erythrocytes and consequent hemolytic anemia. This effect again has been attributed to the aliphatic sulfides. In the present study, the ability of sulfides derived from garlic and onions to generate "active oxygen" species and cause oxidative damage to erythrocytes in vitro has been compared, together with their ability to cause hemolytic anemia and increase the activity of the Phase 2 enzymes quinone reductase (QR) and glutathione S-transferase (GST) in rats. Monosulfides were without significant effect on any parameter. Di-, tri-, and tetrasulfides generated hydrogen peroxide in the presence of GSH and hemoglobin and caused oxidative damage to erythrocytes in vitro. The activity decreased in the order of tetra- > tri- > disulfide, with the allyl compounds being more potent than the propyl. In vivo, both allyl and propyl tri- and tetrasulfides were powerful hemolytic agents. In contrast, only the allyl sulfides increased the activities of QR and GST; the propyl derivatives were completely without effect. Allyl and propyl tri- and tetrasulfides, thus, may contribute to the toxic effects of Allium vegetables, while only the allyl derivatives are effective in increasing tissue activities of cancer-protective enzymes.     

Effect of selenium deficiency and vitamin E deficiency on glutathione metabolism in isolated rat hepatocytes

Selenium deficiency and vitamin E deficiency both affect xenobiotic metabolism and toxicity. In addition, selenium deficiency causes changes in the activity of some glutathione-requiring enzymes. We have studied glutathione metabolism in isolated hepatocytes from selenium-deficient, vitamin E-deficient, and control rats. Cell viability, as measured by trypan blue exclusion, was comparable for all groups during the 5-h incubation. Freshly isolated hepatocytes had the same glutathione concentration regardless of diet group. During the incubation, however, the glutathione concentration in selenium-deficient hepatocytes rose to 1.4 times that in control hepatocytes. The selenium-deficient cells also released twice as much glutathione into the incubation medium as did the control cells. Total glutathione (intracellular plus extracellular) in the incubation flask increased from 47.7 +/- 8.9 to 152 +/- 16.5 nmol/10(6) selenium-deficient cells over 5 h compared with an increase from 46.7 +/- 7.1 to 92.0 +/- 17.4 nmol/10(6) control cells and from 47.7 +/- 11.7 to 79.5 +/- 24.9 nmol/10(6) vitamin E-deficient cells. This overall increase in glutathione concentration suggested that glutathione synthesis was accelerated by selenium deficiency. The activity of gamma-glutamylcysteine synthetase was twice as great in selenium-deficient liver supernatant (105,000 X g) as in vitamin E-deficient or control liver supernatant (105,000 X g). Hemoglobin-free perfused livers were used to determine the form of glutathione released and its route. Selenium-deficient livers released 4 times as much GSH into the caval perfusate as did control livers. Plasma glutathione concentration in selenium-deficient rats was found to be 2-fold that in control rats, suggesting that increased GSH synthesis and release is an in vivo phenomenon associated with selenium deficiency.     

Useful agents for the study of glutathione metabolism in erythrocytes. Organic hydroperoxides

t-Butyl hydroperoxide and cumene hydroperoxide, both known to be substrates for glutathione peroxidase, were used to oxidize erythrocyte GSH. Addition of concentrations of hydroperoxides equimolar with respect to GSH in the erythrocytes or whole blood quantitatively oxidizes GSH in the erythrocytes with a half-time of 4.5s at 37 degrees C and about three times as long at 4 degrees C. In the presence of glucose, normal erythrocytes regenerate all the GSH in about 25min. However, glucose 6-phosphate dehydrogenase-deficient erythrocytes failed to regenerate GSH. Treatment of erythrocytes with hydroperoxides does not affect erythrocyte survival in rabbits. Oxidation of erythrocyte GSH with equimolar concentrations of hydroperoxides does not lead to formation of mixed disulphides of haemoglobin and GSH. The hydroperoxides do not affect erythrocyte glycolytic and hexose monophosphate-shunt-pathway enzymes. Previous studies on transport of GSSG from erythrocytes were confirmed by using t-butyl hydroperoxide to oxidize erythrocyte GSH.     

Inhibition of erythrocyte superoxide dismutase by diethyldithiocarbamate also results in oxyhemoglobin-catalyzed glutathione depletion and methemoglobin production

N,N-Diethyldithiocarbamate (DDC), a copper-chelating agent, not only inhibits superoxide dismutase activity in the red cell, but also depletes glutathione and promotes the production of methemoglobin, sulfhemoglobin, and small amounts of lipid peroxidation products. DDC reacts with oxyhemoglobin to yield disulfiram, hydrogen peroxide, and methemoglobin. Disulfiram and hydrogen peroxide both convert GSH to GSSG, while DDC reduces methemoglobin to oxyhemoglobin. Although disulfiram also reacts with the hemoglobin sulfhydryl groups, this reaction does not play a role in the conversion of GSH to GSSG. Other hemoglobin derivatives, ferrous, and ferric ions do not catalyze the oxidation of GSH by DDC. These results support the conclusion that DDC reacts with the super-oxo-ferriheme complex of oxyhemoglobin to generate hydrogen peroxide and disulfiram and that the cyclic conversion of oxyhemoglobin to methemoglobin and DDC and disulfiram results in the net oxidation of GSH. Thus, damage to DDC-treated erythrocytes exposed to a putative superoxide-generating toxin, such as 1,4-naphthoquinone-2-sulfonate, may actually be due to diminished GSH concentration and hemoglobin oxidation rather than to superoxide radicals. Glucose added to the incubation medium of DDC-treated erythrocytes fully prevented glutathione depletion but not the oxidation of oxyhemoglobin to methemoglobin. Several other copper-chelating agents either failed to inhibit the activity of purified superoxide dismutase or when incubated with erythrocytes produced more extensive GSH depletion and hemoglobin oxidation than DDC. It is concluded that the interpretation of results with erythrocytes exposed to copper-chelating agents must consider their effects on GSH and hemoglobin as well as on superoxide dismutase inhibition. Moreover, one must be mindful of the interference by DDC in the analysis of GSH with 5,5'-dithiobis-(2-nitrobenzoic acid) in the absence of sufficient quantities of metaphosphoric acid to destroy DDC and that contamination of DDC with trace quantities of disulfiram may be a significant problem.     

Erythrocyte and plasma glutathione levels in patients with chronic renal insufficiency

Reduced glutathione (GSH) levels were investigated in the erythrocytes and plasma of nondialyzed patients with varying degrees of renal insufficiency and also of patients on regular hemodialysis treatment. GSH levels were from 19 to 70% higher in the erythrocytes of examined patients as compared to their corresponding age-matched controls. A correlation was found between the degree of renal insufficiency and the erythrocyte GSH level. No variations in plasma GSH levels which could be related to the degree of renal deterioration were observed. A routine hemodialysis did not significantly affect erythrocyte and plasma GSH levels. No significant differences in GSH levels between anemic and nonanemic uremic patients were observed.