Effects of uremic solutes on reactive oxygen species in vitro model systems as a possibility of support the renal function management.

Background: In view of the prevalence of oxidative stress in chronic kidney disease (CKD) patients, the loss of low-molecular-weight biomolecules by hemodialysis and the antioxidant potential of some uremic solutes that accumulate in CKD, we used in vitro model systems to test the antioxidant potential of the following uremic solutes: uric acid, hippuric acid, p-cresol, phenol, methylguanidine, L-arginine, L-tyrosine, creatinine and urea.

Methods: The in vitro antioxidant efficiencies of the uremic solutes, isolated or in mixtures, were tested with the following assays: i) ABTS radical cation decolorization assay; ii) hypochlorous acid (HOCl/OCl(-)) scavenging activity; iii) superoxide anion radical (O2(•-)) scavenging activity; iv) crocin bleaching assay (capture of peroxyl radical, ROO(•)); v) hydrogen peroxide (H2O2) scavenging activity.

Results: Four of the tested uremic solutes (p-cresol, phenol, L-tyrosine, uric acid) were effective antioxidants and their IC50 were found in three model systems: ABTS(•+), HOCl/OCl(-) and crocin bleaching assay.

Lack of Correlation between Periodontitis and Renal Dysfunction in Systemically Healthy Patients.

Objectives: The aim of this study was to assess a suggested association between periodontitis and renal insufficiency by assaying kidney disease markers.

Methods: VARIABLES USED TO DIAGNOSE PERIODONTITIS WERE: (i) probing pocket depth (PPD), (ii) attachment loss (AL), (iii) bleeding on probing (BOP), (iv) plaque index (PI) and (v) extent and severity index. Blood and urine were collected from 60 apparently healthy non-smokers (men and women), consisting of a test group of 30 subjects with periodontitis (age 46±6 yrs) and a control group of 30 healthy subjects (age 43±5 yrs).