title: Effect of erythropoietin therapy and selenium supplementation on selected antioxidant parameters in blood of uremic patients on long-term hemodialysis.
abstract: BACKGROUND
  The kidney accumulates the highest level of selenium (Se) in the organism and is the major source of plasma glutathione peroxidase (GSH-Px). Se, as an integral part of the active site of GSH-Px, plays an important role in protecting cell membranes from oxidative damage. Decreased blood Se levels and GSH-Px activity are common in chronic renal failure (CRF) patients. Our study was an effort to evaluate the effect of erythropoietin (EPO) therapy and Se supplementation for CRF patients undergoing regular hemodialysis (HD) on blood Se, red cell glutathione (GSH), and blood lipid peroxidation product levels, and on blood activity levels of GSH-Px and blood superoxide dismutase (SOD).
  
  
  METHODS
  Our subjects were divided into three groups: I - CRF patients on regular HD and EPO, II - HD patients receiving EPO and Se, and III - healthy controls. Se levels, SOD and GSH-Px activities were measured spectrofluorometrically, the GSH level by Beutler's colorimetric method, and lipid peroxidation products using TBARS.
  
  
  RESULTS
  EPO therapy with Se supplementation significantly increased whole blood and plasma Se in HD patients, and raised red cell GSH-Px activity, but plasma GSH-Px activity, plasma superoxide dismutase, and plasma and red cell TBARS did not respond to Se supplementation. EPO alone showed no effect on these parameters.
  
  
  CONCLUSIONS
  Treatment with EPO and supplementation with Se significantly increased the element concentration in whole blood and plasma, and GSH-Px activity in red cells. Plasma GSH-Px activity did not respond to Se.
authors.affiliation: Department of Nephrology, Medical University, Bydgoszcz, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Adamowicz
authors.forename: Urszula
authors.initials: U
authors.lastname: Trafikowska
authors.forename: Anna
authors.initials: A
authors.lastname: Trafikowska
authors.forename: Bronisław
authors.initials: B
authors.lastname: Zachara
authors.forename: Jacek
authors.initials: J
authors.lastname: Manitius
mesh_terms: D000293:Adolescent; D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D019587:Dietary Supplements; D004921:Erythropoietin / Q000627:therapeutic use*; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012643:Selenium / Q000627:therapeutic use*; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D014511:Uremia / Q000097:blood* / Q000628:therapy*
chemical_list: D000975:Antioxidants; D004921:Erythropoietin; D005979:Glutathione Peroxidase; D012643:Selenium