LOW WHOLE-BLOOD AND ERYTHROCYTE LEVELS OF GLUTATHIONE IN HEMODIALYSISAND PERITONEAL-DIALYSIS PATIENTS

Dialysis patients are reported to have impaired antioxidant mechanisms , including those involving glutathione-dependent enzymes, This study used high-performance liquid chromatography assays that directly measu re total (oxidized + reduced) glutathione and its precursor cysteine ( CYS) to compare the whole blood of hemodialysis (prehemodialysis and p osthemodialysis) and peritoneal dialysis patients to that of blood don ors with no known kidney disease (n = 20 in each group), The levels in erythrocytes were calculated from that data (as nmol/g hemoglobin) be cause these cells are the major compartment of blood glutathione and t heir survival may be shortened by oxidant damage, Both dialysis groups had significantly (P = 0.0001) higher CYS levels in the plasma compar tment than the controls (251 nmol/ml), with prehemodialysis levels (43 2 nmol/mL) being greater than peritoneal dialysis levels (334 nmol/ml) , Hemodialysis acutely lowered CYS levels (215 nmol/mL) below those of controls, Expressed per milliliter whole blood, both dialysis groups had significantly (P = 0.0001) lower glutathione levels than controls (1,276 nmol/mL), with prehemodialysis and peritoneal dialysis levels b eing similar (778 and 912 nmol/ml), Values increased prehemodialysis t o posthemodialysis, consistent with hemoconcentration. Expressed per g ram hemoglobin, the dialysis groups had significantly (P < 0.015) lowe r glutathione levels than the controls (8,938 nmol/g hemoglobin), with similar prehemodialysis, posthemodialysis, and peritoneal dialysis va lues (7,207, 7,315, and 7,915 nmol/g hemoglobin, respectively), In sum mary, hemodialysis and peritoneal dialysis patients are at increased r isk from oxidative stress due to glutathione deficiency in whole blood and erythrocytes, (C) 1997 by the National Kidney Foundation, Inc.