Dialysis is a method of renal replacement therapy in patients with renal failure. Peritoneal dialysis is preferred first use in renal failure, as it is associated with better preservatoin of residual renal function than that seen in hemodialysis and with related benifits (Marrón et al., 2008).
The dialysis procedure contributes to oxidative stress. An increase in oxidative stress may contributes to the development of oxidative protein damage (Dursuna et al., 2005).
Proteolysis products of proteins damaged by oxidation are waste products normally excreted in urine and cleared in dialysate fluid. Increased protein damage has been linked to mortality in end-stage renal disease (Rabban and Thornally, 2009).
The inflammatory status is observed in dialyzed and undialyzed Chronic Renal Failure (CRF) patients. The relationship between oxygen free radicals production and dialysis could play an important role in protein oxidation. Oxidative reactions most frequently involve free-radical intermediates that have direct or indirect participation in the inflammatory response (Morena et al., 2000).
That response is ampilified by the hemobioincompatibiltiy of dialysis systems and solutions, which worsen the pro- oxidant status of uremic patients or which, by activating signaling cascades mediate proliferation, differentiation, and cell death (Wratten et al., 2000).
The accumulation of oxidized proteins depends upon the balance between pro-oxidant, anti-oxidant, and proteolytic activity. That oxidatively modified forms of protiens have been demonestrated to accumulate during oxidative stress and in some pathologic conditions has focused attention on physiologic and non-physiologic mechanisms for the generation of reactive oxygen species (Miyata et al., 2000).
The most common products of protein oxidation in biological samples are carbonyl protein derivatives.These derivatives are chemically stable and serve as markers of oxidative stress for most types of reactive oxygen species. Carbonyl proteins result from the interaction between free radicals and proteins (Berlett and Stadtman, 1997).
They are considered to be mainly 2-Aminoadipic Semi-Aldehyde (AASA) formed from oxidive deamination of lysine, and glutamic semi-aldehyde formed by oxidation of proline and arginine residues (Sell et al., 2007).
These analytes are detected discretely after reduction to 6-hydroxy-2-aminocaproic acid and 5-hydroxy-2-aminovleric acid (Requena et al., 2001).