Serum and erythrocyte glutathione reductase activity in chronic renal failure.

The activity of serum and erythrocyte glutathione reductase was studied in 66 undialysed uremic patients, 19 patients under treatment by chronic hemodialysis and 38 normal subjects. A statistically significant increase of the enzyme activity was found both in serum and erythrocytes in the uremic patients. This increase was in positive correlation with blood urea and creatinine. No difference has been observed in the enzyme activity before and after hemodialysis. By electrophoresis of the hemolysate in cellulose-acetate the pattern of the isoenzymes of the uremic patients was similar to that of the controls.

G-6-PD activity of the red cells in chronic renal failure.

The G-6-PD activity of erythrocytes was studied in 75 patients with chronic renal failure and 74 normal subjects. The mean value of G-6-PD was higher in the chronic renal failure group and the difference was highly significant. During haemodialysis the G-6-PD activity did not return to normal but was further elevated, though the increase was not statistically significant. A highly significant negative correlation was found between red cell G-6-PD and haematocrit. After separation of the red cells according to age by centrifugation, G-6-PD was highest in the top (young cells) and lowest in the bottom (old) cells, both in normals and uraemic patients. The enzyme activity was higher at all levels in the uraemic subjects, significantly in the top and middle layers. Although our findings may be due to an increased proportion of young erythrocytes in uraemia there are objections to this explanation; the alternative possibility of a life-long metabolic abnormality in uraemic red cells deserves careful consideration.