1992 Volume 38 Issue 1 Pages 57-68
Accelerated senescence prone mice and resistant mice (SAM-P/1 and SAM-R/1) were fed 10% casein diet or that supplemented with 2.5% methionine (Met) diet for 4 weeks. Erythrocytes withdrawn from animals of each group were separated by density gradient centrifugation into four fractions of different cell density, that is, different age of erythrocytes, and were analyzed for the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and the level ofoxidized protein. Excess Met decreased the specific activity of GSH-Px in each fraction and the whole population of erythrocytes in SAM-P/1 but not in SAM-R/1. The changes in SOD activities were least significant among the erythrocyte fractions of every dietary group. The oxidized protein level in cell lysate increased with the increase of cell density in both strains of animals. These results were interpreted as indicating that excess Met had a positive effect on the erythrocytes senescence, and suggested that the activity of GSH-Px may be a useful enzymatic marker for the age of erythrocytes.