Publications (2)5.07 Total impact
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Article: Quantitative analysis of cysteine-34 on the anitioxidative properties of human serum albumin in hemodialysis patients.
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ABSTRACT: The purpose of this study was to quantitatively evaluate the extent of contribution of cysteine-34 ((34) Cys) on the antioxidant effect of human serum albumin (HSA) and to elucidate the physiological implication in hemodialysis (HD) patients. The ratio of oxidized albumin correlated directly with the thiol content in plasma of the HD patients who received intravenous iron. Moreover, the degree of oxidation of (34) Cys in HSA purified from the HD patients' plasma correlated with the thiol content in plasma. The radical scavenging activity of purified HSA was dependent on the degree of (34) Cys oxidation. A recombinant mutant, C34S, was produced to confirm the role of (34) Cys. The activity of C34S was about half of that of wild-type HSA (WT-HSA). Consistent with this observation, the protective effects of C34S were significantly lower than those of WT-HSA in suppressing cytotoxicity and vascular endothelial growth factor production induced by fenton reaction in a human vascular endothelial cell model. These results indicate that the (34) Cys residue of HSA may account for more than 40% of the antioxidant effect of HSA in vivo, and thus may exert a protective effect on vascular endothelium function via an antioxidative mechanism in chronic renal disease.Journal of Pharmaceutical Sciences 04/2011; 100(9):3968-76. · 3.06 Impact Factor -
Article: Effect of intravenous iron administration frequency on AOPP and inflammatory biomarkers in chronic hemodialysis patients: a pilot study.
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ABSTRACT: Intravenous iron administration (IVIR) is effective for correcting anemia in hemodialysis (HD) patients, but it also enhances the generation of hydroxyl radicals. Previously we demonstrated that IVIR increases oxidized serum albumin levels in HD patients. However, the effect of IVIR frequencies on the oxidative stress has never been studied before. Therefore, we compared the two IVIR schedules recommended by the Japanese Society for Dialysis Therapy guideline 2004 by measuring oxidized albumin in chronic HD patients. Twenty-two HD patients were divided into two IVIR protocol groups (group I: 40 mg of iron 3 times a week for 4 weeks, group II: 40 mg of iron once a week for 3 months). These protocols differ in IVIR frequency, but receive the same amount of iron (total 520 mg). We compared these two regimens by determining the levels of hemoglobin, serum ferritin, advanced oxidation protein products (AOPP), and oxidized albumin at 0, 4, 8, 12, 16, and 20 weeks. Both patient groups resulted in a similar and significant increase in hemoglobin levels, whereas group I markedly induced AOPP and oxidation of serum albumin than group II at 4 weeks (P<0.05). AOPP and oxidation of serum albumin was also gradually declined by 20 weeks, while the oxidized albumin and AOPP in group II was not significantly changed during the entire experimental period. Transferrin saturation and serum ferritin levels were also increased in group I compared with group II at 4 weeks (P<0.001). In addition, we found a strong positive correlation between oxidized albumin and serum ferritin levels (r=0.615, P<0.05), suggesting the possibility that the accumulation of iron stores has a causative role in the progression of oxidative stress in HD patients treated with IVIR. The results of this study indicate that lower frequency IVIR protocol is recommended to reduce IVIR-induced oxidative stress in HD patients.Clinical biochemistry 07/2008; 41(14-15):1168-74. · 2.02 Impact Factor
