Oxidative stress in elderly chronic renal failure patients: effects of renal replacement therapies on cell membrane fluidity.
BACKGROUND
Renal replacement therapies (RRTs) produce a partial loss of antioxidants and formation of reactive oxygen species (ROS), which are a major factor involved in alterations of plasma membrane fluidity and endothelial activation, but their role on plasma membrane fluidity in vivo is still unclear. We compared erythrocyte plasma membrane fluidity, ROS and total plasma antioxidant defenses (Lagtime) in aged patients with chronic renal failure (CRF) on conservative treatment, peritoneal dialysis (PD) and hemodialysis (HD) before (HD-pre) and after (HD-post) a treatment, to evaluate the role of different RRTs on oxidative stress and plasma membrane fluidity in aged patients.


METHODS
We assessed erythrocyte plasma membrane fluidity, plasma lipid hydroperoxide levels and Lag-Time in 11 CRF patients on conservative treatment, 15 on PD, 12 on HD and 30 healthy controls.


RESULTS
Hydroperoxides were higher in CRF, PD and HD-post, whereas Lag-time was significantly lower in PD, CRF and in HD-post. CRF, PD and HD-pre also had higher membrane fluidity (rsDPH), compared with HD-post and controls.


CONCLUSIONS
These findings are in keeping with the hypothesis that the Lag-time decrease is due not only to the effect of the RRT but also to the uremic state, and that PD patients undergo a chronic, greater oxidative stress. Contrary to expectations, all patients showed greater erythrocyte membrane fluidity, which can be attributed to uremic toxicity. These observations reinforce the hypothesis that oxidative stress is an intrinsic component of this disease state and indeed is already present also in CRF not yet requiring RRT.
Goi
Giancarlo
G
Department of Medical Chemistry, Biochemistry and Biotechnology, University of Milan, Milan, Italy. Giancarlo.goi@unimi.it
Massaccesi
Luca
L
Baquero Herrera
Claudia J
CJ
Musetti
Claudio
C
Ciurlino
Daniele
D
Cusi
Daniele
D
Bertoli
Silvio
S
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism; D016022:Case-Control Studies; D004910:Erythrocyte Membrane / Q000502:physiology*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy*; D008054:Lipid Peroxides / Q000097:blood; D008297:Male; D008560:Membrane Fluidity / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology*; D010530:Peritoneal Dialysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D006435:Renal Dialysis; D017582:Renal Replacement Therapy / Q000379:methods*
D008054:Lipid Peroxides; D017382:Reactive Oxygen Species