ascorbic-acid and uric-acid-riboside

Urate, 3-ribosylurate, ascorbate, glutathione and plasma protected bovine, porcine and human erythrocytes from hemolysis caused by t-butyl hydroperoxide (t-BHP). Urate partially protected porcine erythrocytes from hemolysis by t-BHP when it was added 15 min after the addition of the t-BHP, but it did not protect when added 30 min after the t-BHP. Glutathione and ascorbate protected oxyhemoglobin from oxidation to methemoglobin by t-BHP; 3-ribosylurate gave only slight protection. Urate stimulated the formation of methemoglobin from oxyhemoglobin during treatment with t-BHP.

Topics: Animals; Antioxidants; Ascorbic Acid; Cattle; Erythrocytes; Glutathione; Hemolysis; Humans; Kinetics; Male; Methemoglobin; Peroxides; Ribonucleosides; Species Specificity; Swine; tert-Butylhydroperoxide; Uric Acid

The addition of sodium nitrite to washed bovine erythrocytes incubated in buffered saline resulted in the formation of methemoglobin with a decrease in the concentration of 3-N-ribosyluric acid. The oxyhemoglobin in hemolysates prepared from bovine red cells which contained high concentrations of 3-ribosyluric acid was oxidized to methemoglobin more slowly than oxyhemoglobin from cells with low levels of 3-ribosyluric acid. Oxyhemoglobin from hemolysates that were dialyzed was oxidized more rapidly than oxyhemoglobin which was not dialyzed. 3-Ribosyluric acid, glutathione, uric acid, and ascorbic acid prevented the oxidation of oxyhemoglobin by nitrite. Uric acid protected oxyhemoglobin at the lowest concentration, followed closely by ascorbic acid, 3-ribosyluric acid, and glutathione. Hydrogen peroxide enhanced the oxidation produced by nitrite; this effect was also prevented by the four antioxidants used.

Topics: Animals; Ascorbic Acid; Cattle; Erythrocytes; Glutathione; Hemolysis; Hydrogen Peroxide; In Vitro Techniques; Methemoglobin; Nitrites; Oxidation-Reduction; Oxyhemoglobins; Ribonucleosides; Sodium Nitrite; Uric Acid