Background: Reactive oxygen species are as being related to the pathophysiology of endstage renal disease (ESRD). We measured the plasma hydroxyl radical (.OH)-producing ability and .OH-scavenging activity in patients with ESRD to clarify the pathophysiological states involved.
Methods: We used electron spin resonance to measure plasma N-t-butyl-alpha-phenylnitron radical spin adduct (pPBN rsa) as .OH-producing ability and plasma 3,3,5,5-tetramethyl-1-pyrroline-N-oxide radical spin adduct (pM4PO rsa) as .OH-scavenging activity. Oxidative injuries were evaluated by determining oxidised low-density lipoprotein (Ox-LDL).
Results: The pPBN rsa of the ESRD patients was lower than that of the controls (1.83 vs 2.94 micromol/g protein). The pM4PO rsa of the ESRD patients was higher than that of the controls (3.85 vs 3.15 mmol L: -ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl hydrogen phosphate] potassium salt (EPC-K1)/g protein). The pPBN rsa and pM4PO rsa were correlated, both in the ESRD patients and in the controls (r = 0.47 and r = 0.53). Ox-LDL was correlated with hemodialysis (HD) duration (r = 0.49) and was negatively correlated with pPBN rsa (r = -0.54), which indicates that oxidative stress was increased as HD therapy was prolonged and suppressed pPBN rsa.
Conclusions: There was an imbalance between .OH-producing ability and .OH-scavenging activity, in the ESRD patients, and this may be responsible for compromising the health of ESRD patients.