Reduction of serum antioxidative capacity during hemodialysis.
BACKGROUND
Hemodialysis (HD) is thought to exacerbate oxidative stress (OS). The purpose of this study was to assess patients' oxidative status during and after HD, and to clarify the relation between oxidative status and antioxidant solutes such as uric acid (UA) and ascorbic acid (AsA).


METHODS
Serum diacron-reactive oxygen metabolites (d-ROM), and biological antioxidant potential (BAP), as well as serum concentrations of UA, AsA, urea nitrogen (UN), and creatinine (Cre) were measured in eight HD patients at six time points during and after HD. Inflow and outflow dialyzer blood was evaluated during HD or sham HD (no dialysate flow). Further, BAP was evaluated by adding UA or AsA to post-HD serum.


RESULTS
No changes were found in d-ROM over time, whereas BAP was significantly decreased by HD. No differences were found in d-ROM during HD or sham HD, or between inflow and outflow blood. During HD, significantly lower BAP levels were found in outflow blood than in inflow blood. Serum UA and AsA levels were decreased by HD; however, no increases were observed in BAP levels after the addition of these molecules to post-HD serum.


CONCLUSIONS
These data indicate that HD reduces serum antioxidative capacity, and the loss of dialyzable molecules may be involved. However, this reduction in capacity does not seem to be caused by the loss of UA or AsA.
Nakayama
Keisuke
K
Research Division of Dialysis and Chronic Kidney Disease, Tohoku University Graduate School of Medicine, 1-1 Seiryo machi aoba-ku, Sendai, 980-8574, Japan. nkeisuke@ac.cyberhome.ne.jp.
Terawaki
Hiroyuki
H
Research Division of Dialysis and Chronic Kidney Disease, Tohoku University Graduate School of Medicine, 1-1 Seiryo machi aoba-ku, Sendai, 980-8574, Japan.
Nakayama
Masaaki
M
Research Division of Dialysis and Chronic Kidney Disease, Tohoku University Graduate School of Medicine, 1-1 Seiryo machi aoba-ku, Sendai, 980-8574, Japan.
Iwabuchi
Masashi
M
Department of Blood Purification, Tohoku University Graduate School of Medicine, Sendai, Japan.
Sato
Toshinobu
T
Department of Blood Purification, Tohoku University Graduate School of Medicine, Sendai, Japan.
Ito
Sadayoshi
S
Research Division of Dialysis and Chronic Kidney Disease, Tohoku University Graduate School of Medicine, 1-1 Seiryo machi aoba-ku, Sendai, 980-8574, Japan.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D006435:Renal Dialysis / Q000009:adverse effects*; D014527:Uric Acid / Q000097:blood*
D000975:Antioxidants; D014527:Uric Acid; D001205:Ascorbic Acid