title: Massive and long-lasting decrease in vitamin C plasma levels as a consequence of extracorporeal circulation.
abstract: OBJECTIVE
  The use of cardiopulmonary bypass (CPB) is suggested to induce oxidative stress, reflected by an imbalance between prooxidant and antioxidant substances. The majority of studies published have either focused on only one aspect (prooxidant or antioxidant side) or covered only a short observation period. Therefore, the aim of this study was to investigate the long-term effects of CPB on the balance of prooxidative markers and antioxidant substances in one single group of patients, being able to estimate the degree of oxidative stress.
  
  
  METHODS
  Blood samples were taken from 29 patients undergoing cardiovascular surgery beginning the day before surgery through postoperative day 6 (discharge). Plasma concentrations of vitamins C (total ascorbic acid) and E and malondialdehyde were measured by high-performance liquid chromatography. Plasma levels of ascorbyl free radical were determined using electron paramagnetic resonance spectroscopy.
  
  
  RESULTS
  The study showed a significant decrease in vitamin C plasma levels during CPB without any recovery of vitamin C up to the time of discharge. Furthermore, CPB induced a significant increase in malondialdehyde plasma concentrations immediately after unclamping, accompanied by a significant increase in the ascorbyl free radical to total ascorbic acid ratio. The latter stayed elevated until the end of observation.
  
  
  CONCLUSIONS
  Our findings indicate that the oxidative stress event after CPB can be divided into two phases: Immediately after reperfusion, a massive oxidative stress occurs, reflected by the increase in malondialdehyde. During convalescence, there must be an ongoing situation of oxidative stress, especially in the water-soluble compartment, leading to the consumption of vitamin C. Because the main antioxidant substance, vitamin C, did not increase again over the entire observation period, supplementation should be given consideration.
authors.affiliation: Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany. Electronic address: Sandra.Rodemeister@uni-hohenheim.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Rodemeister
authors.affiliation: Centre hospitalier universitaire Nice, service d'anesthésie-réanimation, Nice, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Duquesne
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University of Tuebingen, Tuebingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Adolph
authors.affiliation: Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany.
authors.forename: Donatus
authors.initials: D
authors.lastname: Nohr
authors.affiliation: Institute for Biological Chemistry and Nutrition, University of Hohenheim, Stuttgart, Germany.
authors.forename: Hans K
authors.initials: HK
authors.lastname: Biesalski
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University of Tuebingen, Tuebingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Unertl
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000097:blood*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000379:methods; D002318:Cardiovascular Diseases / Q000601:surgery; D002851:Chromatography, High Pressure Liquid; D003683:Dehydroascorbic Acid / Q000031:analogs & derivatives / Q000097:blood; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000097:blood
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D014810:Vitamin E; D008315:Malondialdehyde; C000820:semidehydroascorbic acid; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid
keywords: Antioxidants; Ascorbic acid; Ascorbyl free radical; Cardiopulmonary bypass; Cardiovascular surgery; Oxidative stress