Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1260386 (GSH)
 38,102 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Red cells from several animal species were treated with acetylphenylhydrazine and a comparative study of the oxidation of hemoglobin (Hb) and glutathione (GSH) made. Wide interspecies differences were observed but the oxidation of GSH paralleled that of Hb. Added glucose protected both Hb and GSH from oxidation; GSH by itself exercises a protective effect on Hb. The characteristic rates of oxidation of GSH in the different species can be observed only in the presence of oxyhemoglobin but not carboxyhemoblobin or methemoglobin. The oxidation of Hb appears to be the primary event, the oxidation of GSH being a consequence thereof.
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PMID:Oxidant effect of acetylphenylhydrazine: a comparative study with erythrocytes of several animal species. 40 73

The extent of stimulation of methemoglobin (metHb) reduction by selenite depends upon the level of reduced glutathione (GSH) in the erythrocytes. The reason for the species difference in the effect of selenite was discussed with respect to species differences in the GSH levels in erythrocytes.
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PMID:Stimulation of methemoglobin reduction by selenium: a comparative study with erythrocytes of various animals. 63 58

Chloramines, compounds made up of chlorine and ammonia, when present in tap water used for dialysis cause methemoglobinemia and hemolysis. Ascorbic acid addition has been reported to effectively neutralize chloramines in vitro and in patients dialyzed with the single batch dialysis delivery system. We extended these observations to patients dialyzed with the proportioning dialysis delivery system where exposure time of ascorbic acid to chloramines is shorter. This may be important since we found that the half time of the reaction between ascorbic acid and chloramines is 4 minutes. Red cell oxidant sensitivity in 15 patients was assessed by incubating red cells with ascorbate-cyanide and measuring methemoglobin which averaged 2.17 +/- 0.42 g/100 ml (SEM) before dialysis and 2.87 +/- 0.52 g/100 ml after dialysis (NS). Reduced glutathione (GSH) levels were also measured as an index of red cell oxidant damage. GSH decreased from a mean of 7.40 +/- 0.59 micromoles/g Hb before dialysis to 6.98 +/- 0.52 micronmoles/g Hb after dialysis (P less than 0.01). In 2 patients there was no change in 51Cr red cell survival when dialyzed on either the proportioning system or other chloramine free systems. We conclude that addition of ascorbic acid to neutralize chloramines in tap water is also effective when using the proportioning dialysis delivery system.
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PMID:Prevention of chloramine-induced hemolysis in dialyzed patients. 69 6

Ascorbic acid and dehydroascorbic acid penetrate the human erythrocyte membrane. In vitro methemoglobin is reduced nonenzymatically by both substances in concentrations of 10(-2) M to 10(-3) M. Dehydroascorbic acid is reduced nonenzymatically to ascorbic acid by GSH, even with low GSH-content of erythrocytes. Under physiological conditions ascorbic acid induced methemoglobin reduction is far less important than reduction by the NADH dependent methemoglobin reductase system. In methemoglobinemic conditions caused by toxic effects or by congenital methemoglobin reductase deficiency treatment with ascorbic acid is possible. However, critically increased methemoglobin content of the blood higher than 30% makes therapy with methylene blue necessary.
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PMID:[On the mechanism of ascorbic acid induced methemoglobin reduction of human erythrocytes (author's transl)]. 92 9

Aromatic amines with electron-donating substituents are directly activated by pure oxyhemoglobin with formation of ferrihemoglobin. Of these xenobiotics the N-alkylated p-phenylenediamines are particularly active. With N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) cooxidation with oxyhemoglobin was observed by ESR spectroscopy with formation of the arylaminyl free radical (TMPD+*). Since the radical is rapidly reduced by ferrohemoglobin, a catalytic cycle of ferrihemoglobin formation is sustained with initially very low steady-state concentrations of the radical, e.g. below 0.1%. Ferrihemoglobin is also able to oxidize TMPD to the radical, hence the steady-state concentration of TMPD+* rises with increasing ferrihemoglobin. Radicals of the Wurster's type tend to disproportionate at high rates generating reactive quinonediiminium cations which oxidize and arylate cellular thiols like GSH and protein SH groups. Because the disproportionation rate depends on the square of the radical concentration, quenching of the radicals by ferrohemoglobin to protect cellular thiols will be effective as long as the capacity of the methemoglobin reductase system is not overwhelmed. The results indicate that erythrocytes may play a critical role in activation and detoxication of p-phenylenediamines.
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PMID:Quantitative determination by ESR of the arylaminyl free radical during the reaction of N,N,N',N'-tetramethyl-p-phenylenediamine with oxyhemoglobin. 133 23

The antineoplastic drug Carboplatin (CBDCA) was encapsulated in human erythrocytes by means of transient hypotonic hemolysis, followed by isotonic resealing. Up to 5 mg/ml of packed cells could be entrapped, with about 70% cell recovery. In vitro incubation of the CBDCA-loaded erythrocytes in autologous plasma caused a very slow release of the drug from the cells (12% approximately in 3 h). The encapsulation conditions, performed at a low hematocrit, in order to obtain high amounts of the drug inside the carriers, impaired the metabolic properties of the loaded erythrocytes significantly. In particular, an almost complete disappearance of GSH was observed. Analysis of the intraerythrocytic metabolism of CBDCA showed that, in spite of its relatively high stability in aqueous solutions, in hemolysates and in the loaded erythrocytes a significant percentage of CBDCA is rapidly converted to other species that still retain an antiproliferative activity in vitro. This fast conversion could be extensively inhibited by previous conversion of oxyhemoglobin to methemoglobin or carbomonoxyhemoglobin, suggesting an important role of heme iron in this process. Encapsulation of CBDCA in selectively targeted human erythrocytes may represent a therapeutic strategy for increasing the drug concentration in specific organs, notably liver.
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PMID:Interaction of carboplatin with carrier human erythrocytes. 138 19

The erythrocyte glutathione metabolism of 11 children with acute celiac disease (CD), 11 children under gluten free diet with CD and 5 children with cow's milk allergy was compared to that of 11 children with nutritive iron deficiency and to 22 healthy children as controls. Erythrocyte glutathione (GSH) content of celiac children was elevated and the glutathione disulfide (GSSG) level was significantly decreased as compared to normal controls. Erythrocyte GSSG/GSH ratio in acute CD differed also from the one in iron deficiency. In vitro oxidative load of acetylphenylhydrazine proved the impaired glutathione stability of the erythrocytes in acute CD and cow's milk allergy. A parallel rise of methemoglobin and hemichrome level of blood cells was seen. Further on, the selenium content of the red blood cells of CD patients decreased. All alterations of the erythrocyte tended to normalize during the dietetic period. These data suggest a reduced protective capacity of erythrocytes in CD and in cow's milk allergy in childhood against oxidizing stresses.
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PMID:Decrease in the antioxidant capacity of red blood cells in children with celiac disease. 147 83

One month-old male Sprague-Dawley rats were maintained on a basal vitamin E-deficient diet supplemented with either 0 or 50 ppm vitamin E for 5 months. Washed red blood cells were resuspended in phosphate buffered-saline, pH 7.4, that contained 0-50 mM glucose and 0-20 mM ethylenediamine tetraacetic acid (EDTA), and were incubated at 37 degrees C for up to 22 h. Contrary to expectations, glucose in the incubation medium accelerated, rather than retarded, the rates of hemolysis, lipid peroxidation and methemoglobin formation in the vitamin E-deficient cells. EDTA, on the other hand, partially inhibited the extent of oxidative damage. Vitamin E-supplemented cells were resistant to oxidative damage in the presence or absence of glucose and/or EDTA. The levels of reduced glutathione (GSH) and activity of catalase were decreased faster in the vitamin E-deficient cells than the supplemented cells, and the rates of their decline were slowed down by either glucose or EDTA. The activities of GSH peroxidase and superoxide dismutase were not significantly altered in the red cells of either group during incubation. The results obtained suggest that reactive oxygen species and reduced metal ions play important roles in initiating oxidative damage to the red cells of vitamin E-deficient rats. However, the agent responsible for initiating the hemolytic event has yet to be established.
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PMID:Oxidative damage in the red cells of vitamin E-deficient rats. 150 85

The effect of acrylonitrile (VCN) on erythrocyte lipid metabolism was investigated in vitro in metabolically active red cells from male Sprague-Dawley rats containing three types of hemoglobins: oxyhemoglobin, methemoglobin, and carbon monoxyhemoglobin. VCN at the concentration of 10 mM rapidly depleted erythrocyte glutathione (GSH) (75% of control) and induced lipid peroxidation (274% of control). Degradation of oxy- and methemoglobin was directly proportional to the extent of lipid peroxidation (r = 0.89). Addition of glucose to the incubation medium decreased hemoglobin degradation while it slightly increased VCN-induced lipid peroxidation. The highest amount of lipid peroxidation occurred in erythrocytes containing carbon monoxyhemoglobin and glucose. In the isolated red cell membranes incubated with 10 mM VCN, the lipid peroxidation was 400% of controls. VCN (25 mM) noncompetitively inhibited erythrocyte membrane Na+/K(+)-ATPase activity and the degree of inhibition was inversely proportional to the reaction temperature (r = -0.88). These findings indicate that the VCN induced hemoglobin degradation and lipid peroxidation are two extremes of a spectrum of oxidative damage in red cells leading to a change in physical state of membrane structure causing inhibition of adenosine triphosphate (ATPase) activity.
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PMID:Hemoglobin degradation, lipid peroxidation, and inhibition of Na+/K(+)-ATPase in rat erythrocytes exposed to acrylonitrile. 196 27

Salivary peroxidase and to a lesser extent myeloperoxidase are present in significant concentrations in saliva and catalyze the oxidation of thiocyanate anion (SCN-) by H2O2 to yield the potent oxidants hypothiocyanous acid (HOSCN) and its conjugate base hypothiocyanite anion (OSCN-). The objective of this study was to characterize the cytotoxic potential of peroxidase-generated HOSCN/OSCN- toward human erythrocytes. We found that HOSCN/OSCN- (0.25 mM) generated by the peroxidase-H2O2-SCN- system caused significant hemolysis at pH 6.0 but not at pH 6.5, 7.0, or 7.4. Erythrocyte hemoglobin (OxyHb) was oxidized to methemoglobin (MetHb) at all pH values tested; however, the rate of MetHb formation was dramatically increased at low pH and was not affected by inosine hexaphosphate, suggesting that hemoglobin was oxidized primarily by HOSCN. Concurrent with oxidation of hemoglobin (Hb), there was a pH-dependent consumption of HOSCN/OSCN- with more of the oxidant consumed at pH 6.0 compared with pH 6.5, 7.0, or 7.4. The enhanced oxidation of Hb at acidic pH was not due simply to increased membrane permeability by the uncharged species (HOSCN), since both erythrocyte lysate Hb and purified Hb were oxidized to the same extent at low pH as were intact erythrocytes. It is concluded that both OSCN- and HOSCN enter human erythrocytes where the protonated oxidant (HOSCN) mediates hemolysis and oxidizes OxyHb to MetHb, whereas both HOSCN and OSCN- oxidize glutathione (GSH). These data suggest that the extracellular pH may play an important role in modulating the cytotoxic properties of salivary oxidants.
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PMID:Cytotoxic properties of salivary oxidants. 215 9


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