title: Effect of cigarette smoking on the oxidant/antioxidant balance in healthy subjects.
abstract: OBJECTIVE
  Cigarette smoking has been associated with the development of cardiovascular disease and cancer. Even though the molecular mechanism(s) are not clear, the pathology has been related to oxygen free radicals present in cigarette smoke. Thus, the main objective of this study was to establish the changes in the oxidation/antioxidation balance induced by cigarette smoking.
  
  
  METHODS
  Thirty healthy subjects (15 smokers and 15 nonsmokers) of both sexes were studied. The smokers group had smoked a mean of 14 cigarettes per day for an average of 4.5 years. Fasting serum levels of malondialdehyde (MDA), a marker of oxidative stress, nitric oxide (NO), reduced glutathione (GSH), and vitamin C (ascorbic and dehydroascorbic acids) were measured.
  
  
  RESULTS
  Fasting NO concentration was significantly higher in smokers (51.3 +/- 5.3 microM) than in nonsmokers (35.2 +/- 4.8 microM, P < 0.05). The smokers had significantly higher serum dehydroascorbic acid levels (2.4 +/- 0.5 mg/dL, P < 0.03) than the nonsmokers (1.08 +/- 0.08 mg/dL). No significant differences were observed in the levels of ascorbic acid, MDA, and GSH between the smokers and nonsmokers.
  
  
  CONCLUSIONS
  Our results suggest that exposure to cigarette smoke increases NO synthesis, such that NO may act in a compensatory way as an inhibitor of lipid peroxidation. Smoking also activates other antioxidative mechanisms such as involving vitamin C. These protective mechanisms appear to be enough in preventing accumulation of oxidative products such as MDA and avoiding oxidative damage.
authors.affiliation: Physiology Department, School of Medicine, University of Zulia, Maracaibo, Venezuela.
authors.forename: Jennifier
authors.initials: J
authors.lastname: Chávez
authors.forename: Clímaco
authors.initials: C
authors.lastname: Cano
authors.forename: Aida
authors.initials: A
authors.lastname: Souki
authors.forename: Valmore
authors.initials: V
authors.lastname: Bermúdez
authors.forename: Mayerlim
authors.initials: M
authors.lastname: Medina
authors.forename: Ana
authors.initials: A
authors.lastname: Ciszek
authors.forename: Anilsa
authors.initials: A
authors.lastname: Amell
authors.forename: Maria E
authors.initials: ME
authors.lastname: Vargas
authors.forename: Nadia
authors.initials: N
authors.lastname: Reyna
authors.forename: Abdon
authors.initials: A
authors.lastname: Toledo
authors.forename: Raquel
authors.initials: R
authors.lastname: Cano
authors.forename: Gustavo
authors.initials: G
authors.lastname: Suárez
authors.forename: Freddy
authors.initials: F
authors.lastname: Contreras
authors.forename: Zafar H
authors.initials: ZH
authors.lastname: Israili
authors.forename: Rafael
authors.initials: R
authors.lastname: Hernández-Hernández
authors.forename: Manuel
authors.initials: M
authors.lastname: Valasco
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D003683:Dehydroascorbic Acid / Q000097:blood; D005260:Female; D005978:Glutathione / Q000097:blood; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D009569:Nitric Oxide / Q000097:blood; D016877:Oxidants / Q000378:metabolism*; D010084:Oxidation-Reduction; D012907:Smoking / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D016877:Oxidants; D009569:Nitric Oxide; D008315:Malondialdehyde; D005978:Glutathione; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid