title: Oxidative stress is evident in erythrocytes as well as plasma in patients undergoing heart surgery involving cardiopulmonary bypass.
abstract: OBJECTIVE
  The aim of this study was to analyse the level and progression of oxidative stress, in both plasma and erythrocytes, during heart surgery involving cardiopulmonary bypass.
  
  
  METHODS
  Twenty two patients undergoing cardiac surgery and considered to present a high/severe level of surgical risk were selected. We took five blood samples at different times during the cardiac surgery and analysed TBARS, alpha-tocopherol, coenzyme Q and retinol in plasma and TBARS (baseline levels and induced by Fe2+-ascorbate oxidation), alpha-tocopherol, coenzyme Q and catalase, superoxide dismutase and gluthatione peroxidase activity in erythrocytes.
  
  
  RESULTS
  Plasma results shown a decrease in both alpha-tocopherol and retinol concentration after starting CPB with respect to the reference level (13.6 +/- 1.5 nmol ml(-1) vs. 22.0 +/- 3.0 nmol ml(-1) and 1.2 +/- 0.1nmol ml(-1) vs. 1.8 +/- 0.2 nmol ml(-1), respectively (p < 0.05)). In comparison, in erythrocytes, all antioxidants, both enzymatic and non-enzymatic, increased in activity or concentration after starting CPB. Erythrocyte TBARS, both baseline levels and induced levels, followed a similar pattern, with an increase after starting CPB with respect to the reference level (3.9 +/- 0.6 nmol mg(-1) of protein vs. 2.3 +/- 0.2 nmol mg(-1) of protein and 10.6 +/- 0.8 nmol mg(-1) of protein vs. 6.7+/- 0.6 nmol mg(-1) of protein, respectively (p < 0.05)).
  
  
  CONCLUSIONS
  These results reveal an increase in oxidative stress after CPB, both in plasma and erythrocytes, and although the organism is capable of attenuating this stress by means of various antioxidative defence mechanisms, there is an increased possibility of post-CPB complications and thus of mortality.
authors.affiliation: Departmet of Physiology, Institute of Nutrition and Food Technology (INYTA), University of Granada, C/Ramón Y. Cajal, 4, 18071 Granda, Spain. jjoh@ugr.es
authors.forename: Julio J
authors.initials: JJ
authors.lastname: Ochoa
authors.forename: María J
authors.initials: MJ
authors.lastname: Vílchez
authors.forename: Susana
authors.initials: S
authors.lastname: Ibáñez
authors.forename: Jesús R
authors.initials: JR
authors.lastname: Huertas
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Palacio
authors.forename: Antonio
authors.initials: A
authors.lastname: Muñoz-Hoyos
mesh_terms: D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002374:Catalase / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008875:Middle Aged; D018384:Oxidative Stress; D010949:Plasma / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000097:blood; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D014451:Ubiquinone / Q000097:blood; D014801:Vitamin A / Q000097:blood; D024502:alpha-Tocopherol / Q000097:blood
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D014801:Vitamin A; D014451:Ubiquinone; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D024502:alpha-Tocopherol