Glutathione peroxidase (glutathione--H2O2 oxidoreductase; EC 1.11.1.9) was purified to homogeneity from human placenta by using (NH4)2SO4 precipitation, ion-exchange chromatography, Sephadex gel filtration and preparative polyacrylamide-disc-gel electrophoresis. Glutathione peroxidase from human placenta is a tetramer, having 4g-atoms of selenium/mol of protein. The molecular weight of the enzy...

Protection of nitrogenase against oxygen inactivation in diazotrophs involves numerous strategies. Glutathione is known to play an important role in scavenging oxyradicals in many living systems. The involvement of glutathione (reduced) (GSH), glutathione peroxidase (GPX) and glutathione reductase (GR) in the protection of nitrogenase in free living diazotrophs is reported here for the first ti...

The influence of histamine and quercetin, as well their combined effect on the content in whole blood, superoxide anion radical, sialic acids, sulfhydryl groups, activity catalase, glutathione peroxidase, transferase rat erythrocytes was studied. It established that quercetin at a concentration 0.1 mM causes an increase blood rats, while all other studied concentrations cause significant decrea...

Age-related macular degeneration (ARMD) may result from events initiated by reactive oxygen species. Blood samples from 18 patients with ARMD and 18 similarly aged controls were analysed for activities of important antioxidants. Blood glutathione reductase activity was lower in patients with ARMD compared with controls (p = 0.035). The activities of glutathione peroxidase (p = 0.18) and erythro...

During plant-pathogen interactions, the plant may mount several types of defense responses to either block the pathogen completely or ameliorate the amount of disease. Such responses include release of reactive oxygen species (ROS) to attack the pathogen, as well as formation of cell wall appositions (CWAs) to physically block pathogen penetration. A successful pathogen will likely have its own...

The uteri, spontaneously active or Ca(2+) (6 mM) induced, were allowed to equilibrate, and to inhibit voltage-gated potassium (K(V)) channels 1 mM 4-amino pyridine (4-AP) was applied for 15 min before adding H(2)O(2). H(2)O(2) was added cumulatively: 2 μM, 20 μM, 200 μM, 400 μM, and 3 mM. Average time for H(2)O(2) concentrations (2, 20, 200, and 400) μM to reach its full effect was 15 min. H(2)...

The potential protective effects of taurine and quercetin against gentamycin (GM)/diclofenac (DC) combined nephrotoxicity were investigated in rats. The results showed that administration of DC alone at an oral dose of 5 mg/kg b.wt/day for 28 days had no significant effect on the measured parameters, except for marked increase in urinary uronic acid excretion. Administration of GM alone at a do...

In the present study we investigated the effects of simvastatin treatment on lipid metabolism and peroxidation, antioxidant enzyme activities and ultrastructure of the diabetic rat myocardium. Diabetes was induced by single injection of streptozotocin (45 mg/kg i.p.). Eight weeks after induction of diabetes, a subgroup of control and of diabetic rats was treated with simvastatin for 4 weeks (10...

In the presence of high glucose concentration (16.7 mM), pancreatic islets show increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSHPx). This activation may be a result of reactive oxygen species (ROS) stimulation, which is generated during glucose metabolism. NAD(P)H oxidase is mainly responsible for ROS production by phagocytic cells but its isoforms have been fo...

Studies with 75Se have shown the existence of a rat plasma selenoprotein in addition to glutathione peroxidase. Because the function of the protein is not known, it has been referred to as selenoprotein P. A partially purified preparation was used to produce a monoclonal antibody to selenoprotein P. The antibody did not bind glutathione peroxidase as evidenced by its failure to remove glutathio...