Activation of red blood cell glutathione peroxidase and morphological transformation of erythrocytes under the action of tert-butyl hydroperoxide (original) (raw)
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T-Butyl Hydroperoxide-Induced Perturbations of Human Erythrocytes as a Model for Oxidant Stress
Biochimica et Biophysica Acta (BBA) - Biomembranes, 1985
Erythrocytes were incubated with t-butyl hydroperoxide in the presence and absence of hemoglobin as a model system for oxidative stress and the alterations in the structure and integrity of the membranes were investigated. The results showed that in the presence of hemoglobin a significant modification in the membrane surface charge was induced but no such alteration was observed in peroxidised hemoglobin-free membranes. As increased hemoglobin oxidation occmTed in the erythrocytes, membrane lipid peroxidation diminished, suggesting a protective role for methemoglobin in t-butyl hydroperoxide-induced lipid peroxidation. Electrophoresis on polyacrylamide gels showed modification of the cytoplasmic protein region but no high molecular weight aggregates formed at the concentrations of the hydroperoxide used in this work. The results suggest that the t-butyl hydroperoxide/normal erythrocyte system seems to be an instructive model for membrane perturbations characteristic of oxidative disorders.
Folia morphologica
A short chain synthetic analogue of lipid hydroperoxides was used to overload glutathione peroxidase (GPx) in human choriocarcinoma cell line JAR cells. Cells exposed to 100 µM tBuOOH displayed a 40% reduction in ATP level and significantly increased in membrane permeability, visualised by the lactate dehydrogenase (LDH) release into the extracellular medium. The intracellular level of oxygen free radicals measured as an oxidation of the dichlorodihydro-fluorescein diacetate (H 2 DCF-DA) significantly increased after 2 hours of cell exposition to 100 µM tBuOOH. Concomitantly MDA, 4-HNE level increased to 2 nmol/mg of cell protein after 2 hours. Mitochondria stained with MitoTracker Red CMXRos displayed a filamentous appearance in control cells but changed into granular less energised organelles after exposition to tBuOOH. Collectively, the above results indicate the importance of the contribution of oxidative stress in the development of pre-eclampsia.
Blood, 1989
Genetic deficiencies of glucose-6-phosphate dehydrogenase (G6PD) and NADPH predispose affected erythrocytes to destruction from peroxides. Conversely, genetic deficiencies of catalase do not predispose affected erythrocytes to peroxide-induced destruction. These observations have served to strengthen the assumption that the NADPH/glutathione/glutathione peroxidase pathway is the principal means for disposal of H2O2 in human erythrocytes. Recently, however, mammalian catalase was found to have tightly bound NADPH and to require NADPH for the prevention and reversal of inactivation by its toxic substrate (H2O2). Since both catalase and the glutathione pathway are dependent on NADPH for function, this finding raises the possibility that both mechanisms destroy H2O2 in human erythrocytes. A comparison of normal and acatalasemic erythrocytes in the present study indicated that catalase accounts for more than half of the destruction of H2O2 when H2O2 is generated at a rate comparable to t...
Clinica Chimica Acta, 1993
Inactivation of glutathione peroxidase correlates with the rate of hemoglobin chain oxidation. The enzyme inactivation is mainly present in those conditions where the autoxidation of the oxygenated chains is followed by trasformation of the oxidized molecule into a hemichrome. Free hemoglobin chains have been encaps,dated i~' human red blood cells by a dialysis technique that involves transient hypotonic hemolysis followed by isotonic resealing Chain-loaded erythrocytes represent a good in vitro model of thalassemia. The presence of free human chains in the cell alters the intraerythrocytic glutathione peroxidase activity (oL chains are more effective in the inactivation of the enzyme with respect to the 0 chains).
Biochimica et Biophysica Acta (BBA) - General Subjects, 1983
Free radical involvement in the oxidative events induced by ten-butyl hydroperoxide in erythrocytes has been demonstrated by the use of the electron spin resonance technique of spin trapping with the spin trap 5.5-dimethyl-l-pyrroline-N-oxide (DMPO). The reactions of tert-butyi hydroperoxide with haemoglobins and intact cell systems were studied. Oxyhaemogiobin-containing system showed exclusive production of the t-butyloxy radical spin adduct of DMPO (DMPO-OBut), indicating t-butyloxy radical production. Methaemoglobin-containing systems showed the production of an oxidised derivative of DMPO, 5,5-dimethyl-2-ketopyrrolidino-l-oxyl (DMPOX)-previously associated with the generation of highly oxidised haem-iron. Carbon monoxyhaemoglobin-containing systems show the production of both DMPO-OBff and DMPOX but markedly slower than in either of the other haemoglobin systems. Generally, free radical production in haemoglobin systems was faster than in intact cell systems, indicating a membrane transport rate-limiting step for the tert-butyl hydroperoxide-mediated effects. Data from the use of free radical scavengers to inhibit DMPO-OBff production was consistent with the known reactivities of the scavengers toward t-butyioxy radicals. These and previously reported results (Trotta, R.J., Biochim. Biophys. Acta 679, 230-237 and (1982) Biochem. J. 204, 405-415) implicate important roles for t-butyloxy radicals and haem intermediates in tert-butyl hydroperoxide-induced lipid peroxidation and haemoglobin oxidation in erythrocytes, respectively.
North American Journal of Medical Sciences, 2011
Background: The oxidative stress is considered as major consequence of diabetes mellitus affecting red cell antioxidant enzymes. Aim: The present study was conducted to assess the impact of oxidative stress (reduced glutathione) on glutathione peroxidase, and glutathione reductse and prevalence of anemia among diabetic patients. Materials and Methods: The study involved 100 adult patients attending Buraidah Central Hospital and 30 healthy controls. Blood samples were collected and analyzed for glutathione (GSH) concentration, glutathione peroxidase (GPO), glutathione reductase (GR), fasting blood sugar (RBS), hemoglobin (HGB), red cell count (RBCs) hematocrit (HCT) mean cell volume (MCV) mean cell hemoglobin (MCH) and mean cell hemoglobin concentration (MCHC) and hemoglobin A1c. Blood urea, serum creatinine, and microalbuminuria were measured to exclude diabetes mellitus nephropathy. Results: were obtained showed significant correlation between deficiency of glutathione peroxidase, glutathione reductase and deficient of glutathione among diabetics, which has significant correlation between low hemoglobin concentration (females <120 g/L, males <130 g/L), also there is low concentration of red cell count and red cell indices (MCV, MCH and MCHC). The prevalence of anemia was 22% in diabetes patients. Conclusion: It can be concluded that there is strong significant effect of oxidative stress (reduced glutathione) on glutathione peroxidase, glutathione reductase level these may reduce hemoglobin concentration in diabetic patients. This means oxidative stress of diabetes mellitus is the possible cause of anemia in diabetics without nephropathy.
Peroxidation-induced perturbations of erythrocyte lipid organization
Biochimica et Biophysica Acta (BBA) - Biomembranes, 1990
Peroxidation of erythrocyte membrane lipids by hydrogen peroxide perturbs the lipid bilayer and increases phagocytosis by macrophages. This study addresses the underlying mechanism of these processes, and in particular the role of malondiaidehyde, a major byproduct of lipid peroxidation. When erythrocytes were treated with hydrogen peroxide or ascorhate/iron to generate malondialdehyde, or with malondialdehyde itself, only those cells treated with hydrogen peroxide showed increased phospholipid spacing and enhanced phagocytosis. This result indicates that the alterations observed are unique to hydrogen peroxide treatment, and that malondialdehyde does not play a role in inducing these changes in surface properties.