Glutathione Peroxidase in Human Red Cells in Health and Disease

Abstract

Summary. Red‐cell glutathione peroxidase (GSH‐Px) activity has been assayed in 62 normal subjects and in 163 patients with various diseases. In nine cases of iron deficiency anaemia, the mean GSH‐Px activity per cell or per volume of cells was low; during the first 2–4 weeks of treatment with iron, red‐cell GSH‐Px increased in parallel with haemoglobin. High enzyme activities, above the normal range, were found in 11 cases of megaloblastic anaemia due to deficiency of vitamin B12; rapid and marked fall in GSH‐Px activity followed the start of vitamin B12 therapy. Abnormally high values for red‐cell GSH‐Px were found in acute myeloblastic leukaemia and in myelofibrosis whereas the enzyme activity tended to be low in chronic lymphocytic and in chronic myeloid leukaemia. In two cases of chronic myeloid leukaemia, red‐cell GSH‐Px increased to normal during the early stage of remission produced by cytotoxic therapy. Normal red‐cell GSH‐Px was found in six cases of polycythaemia vera. In patients with carcinoma, there was a wide variation in red‐cell GSH‐Px but the mean value was significantly less than normal.

THE EFFECTS OF DRUGS ON ERYTHROCYTES in vitro: HEINZ BODY FORMATION, GLUTATHIONE PEROXIDASE INHIBITION AND CHANGES IN MECHANICAL FRAGILITY

“…The activity of erythrocyte glutathione peroxidase (EC 1.11.1.9) was measured by a modification (Hopkins & Tudhope, 1973) of the method of Paglia & Valentine (1967), and expressed as a percentage of that of a control incubation, set up similarly except with the omission of drug. Erythrocytes were stained for Heinz bodies using crystal violet.…”

Influence of Exopolysaccharide-Producing Bacteria and SiO2 Nanoparticles on Proline Content and Antioxidant Enzyme Activities of Tomato Seedlings (Solanum lycopersicum L.) under Salinity Stress

“…One unit of catalase activity (U) was assumed to be the amount of enzyme that decomposed 1 μmol H2O2/mg soluble protein per minute. Peroxidase activity: The method of Hopkins and Tudhope [19], with t-butyl hydroperoxide as a substrate, was used. The reaction mixture comprised 50 mM potassium phosphate buffer, pH 7.0, 2 mM EDTA, 0.28 mM NADPH, 0.13 mM GSH, 0.16 U GR, 0.073 mM t-butyl hydroperoxide, and enzyme extract (50 mg protein).…”

Intercompartmental differences between cytosol and mitochondria in their respective antioxidative responses and lipid peroxidation levels in acid rain stress

“…To detect GSH-Px activity, the method of Hopkins and Tudhope (1973) with t-butyl hydroperoxide as a substrate was used. The reaction mixture comprised 50 mM potassium phosphate buffer pH 7.0, 2 mM EDTA, 0.28 lM NADPH?H ?…”