Antioxidant status and dialysis: Plasma and saliva antioxidant activity inpatients with fluctuating urate levels

The present study is concerned with the influence of processes occurring du ring dialysis on the antioxidant capacity of plasma and saliva. The biologi cal fluids were also tested for uric acid and total protein content. Before hemodialysis, plasma antioxidant status of hemodialyzed patients appears s lightly higher than the corresponding status in normal subjects; after hemo dialysis it is found unchanged. The result can be explained by a balance be tween a reduction in uric acid plasma content, due to the dialytic procedur e, and an increase in protein content, possibly due to a dialysis-related h emoconcentration. Moreover, pre-dialysis total antioxidant capacity of whol e saliva samples is higher than in healthy individuals and drastically decr eases towards normal values following dialytic procedure. Our data indicate a certain concentration of the uric acid in the saliva of hemodialyzed pat ients and evidence that both total protein concentration and uric acid leve l show a good correlation with saliva total antioxidant capacity, suggestin g that proteins are major antioxidants of this fluid. Further observations are needed to assess whether this improved saliva antioxidant ability has a ny consequence on the periodontal conditions of hemodialyzed subjects.