Abstract
Oxidative stress is enhanced in regular hemodialysis (HD) patients. Oxidized albumin is a reliable marker of oxidative stress. Depending on redox state, there are three major fractions of human serum albumin (HSA); HMA (reduced form) with a free thiol group on cysteine-34, HNA-1 (reversible oxidation product) with cystine, HNA-2 (irreversible oxidation product) with more oxidized state. We have studied the albumin thiol oxidation and the serum protein carbonyl formation in 21 HD patients. Albumin fractions were analyzed by HPLC and carbonyl content of protein (CC) was determined by Protein Carbonyl Assay Kit. The mean values for f (HMA) pre- and post-HD session were 46.6 ± 8.5% and 66.0 ± 8.9% respectively. In contrast, f (HNA-1) was significantly decreased the course of the HD session (48.2 ± 8.2% at pre-, 30.3 ± 8.3% at post-HD), and f (HNA-2) was also decreased (5.2 ± 1.0% at pre-, 3.7 ± 0.8% at post-HD). CC was also decreased (0.9 ± 0.2 nM/mg protein at pre-, 0.7 ± 0.2 nM/mg protein at post-HD). In relationship between the thiol oxidation and the carbonyl formation, value for CC was not correlated with that for HNA-1 (R = 0.3, P = 0.06) but significantly with that for HNA-2 (R = 0.6, P < 0.0001). We found the close relationship between irreversible oxidation of HSA and serum protein carbonyl formation in HD patients. [J Physiol Sci. 2008;58 Suppl:S114]
