title: Effect of vitamin E on linoleic acid-mediated induction of peroxisomal enzymes in cultured porcine endothelial cells.
abstract: Linoleic acid decreases endothelial barrier function in culture. We hypothesize that the mechanism may involve induction of peroxisomes, with subsequent generation of hydrogen peroxide, and that vitamin E may protect against barrier function loss by preventing the induction of peroxisomal enzymes. To investigate this hypothesis, we exposed cultured endothelial cells to 0 or 90 mumols/L linoleic acid [18:2(n-6)], with or without 25 mumols/L supplemental vitamin E, for 5 d. The induction of peroxisomes by linoleic acid exposure was determined by measuring cellular peroxisomal beta-oxidation and catalase activity. Vitamin E alone had no effect on beta-oxidation or catalase activity, whereas linoleic acid exposure significantly increased both compared with control values. Vitamin E supplementation prevented induction of peroxisomal beta-oxidation and catalase activity by 18:2. In contrast, cell enrichment with vitamin E had no effect on 18:2-induced accumulation of cytoplasmic lipid-like droplets. These results confirm our hypothesis that the protective effects of vitamin E against fatty acid-mediated endothelial cell injury may be due in part to the ability of vitamin E to prevent the induction of peroxisomal beta-oxidation enzymes and thus the formation of excess hydrogen peroxide.
authors.affiliation: Department of Nutrition and Food Science, University of Kentucky, Lexington 40506.
authors.forename: B
authors.initials: B
authors.lastname: Hennig
authors.forename: G A
authors.initials: GA
authors.lastname: Boissonneault
authors.forename: C K
authors.initials: CK
authors.lastname: Chow
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: D H
authors.initials: DH
authors.lastname: Matulionis
authors.forename: H P
authors.initials: HP
authors.lastname: Glauert
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism*; D002478:Cells, Cultured; D004357:Drug Synergism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D004790:Enzyme Induction / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000494:pharmacology*; D008830:Microbodies / Q000187:drug effects; D013552:Swine; D014810:Vitamin E / Q000494:pharmacology*
chemical_list: D008041:Linoleic Acids; D014810:Vitamin E; D019787:Linoleic Acid; D006861:Hydrogen Peroxide; D002374:Catalase