title: Vitamin E regulates changes in tissue antioxidants induced by fish oil and acute exercise.
abstract: OBJECTIVE
  Prooxidant effects of fish oil supplementation could unfavorably affect the cardiovascular benefits of fish oil. We tested the effects of 8 wk vitamin E cosupplementation with fish oil on antioxidant defenses at rest and in response to exhaustive exercise in rats.
  
  
  METHODS
  Rats (N = 80) were divided into fish oil, fish oil and vitamin E (FOVE), soy oil, and soy oil and vitamin E (SOVE) supplemented groups. For the vitamin E supplemented rats, corresponding groups (FOVE-Ex and SOVE-Ex) performed an acute bout of exhaustive exercise after the supplementation period.
  
  
  RESULTS
  Fish oil supplementation increased the activity of catalase, glutathione peroxidase, and glutathione-S-transferase in the liver and red gastrocnemius (RG) muscle. Fish oil decreased liver total glutathione (TGSH) levels. Vitamin E supplementation decreased antioxidant enzyme activities to levels at or near those in SOVE in a tissue specific pattern. Vitamin E increased TGSH in liver, heart, and RG. Regression analysis showed TGSH to be a negative determinant of protein oxidative damage as measured by protein carbonyl levels in both liver and RG. Catalase activity was associated with liver lipid peroxidation as measured by thiobarbituric acid-reacting substances. The exercise-induced decrease in hepatic TGSH tended to be less in FOVE versus SOVE. Exhaustive exercise also modulated tissue antioxidant enzymes.
  
  
  CONCLUSIONS
  Vitamin E supplementation markedly decreased fish oil induced antioxidant enzyme activities in all tissues. Sparing of glutathione may be an important mechanism by which vitamin E decreased tissue protein oxidative damage.
authors.affiliation: Department of Physiology and National Laboratory Animal Center University of Kuopio, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Atalay
authors.forename: D E
authors.initials: DE
authors.lastname: Laaksonen
authors.forename: S
authors.initials: S
authors.lastname: Khanna
authors.forename: E
authors.initials: E
authors.lastname: Kaliste-Korhonen
authors.forename: O
authors.initials: O
authors.lastname: Hänninen
authors.forename: C K
authors.initials: CK
authors.lastname: Sen
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D019587:Dietary Supplements; D004347:Drug Interactions; D005395:Fish Oils / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D015227:Lipid Peroxidation; D008297:Male; D018384:Oxidative Stress; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D005395:Fish Oils; D014810:Vitamin E; D005978:Glutathione