title: Dietary n-3 HUFA affects mitochondrial fatty acid beta-oxidation capacity and susceptibility to oxidative stress in Atlantic salmon.
abstract: Atlantic salmon (Salmo salar) (90 g) were fed four different diets for 21 weeks (final weight 344 g). The levels of n-3 highly unsaturated fatty acids (HUFA) ranged from 11% of the total fatty acids (FA) in the low n-3 diet to 21% in the intermediate n-3 diet, to 55 and 58% in the high n-3 diets. The high n-3 diets were enriched with either docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA). Increasing dietary levels of n-3 HUFA led to increasing percentages (from 31 to 52%) of these FA in liver lipids. The group fed the highest level of DHA had higher expressions of peroxisome proliferator-activated receptor (PPAR) beta and the FA beta-oxidation genes acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase (CPT)-II, compared to the low n-3 groups. The high n-3 groups had reduced activity of mitochondrial cytochrome c oxidase and beta-oxidation capacity, together with increased activities of superoxide dismutase (SOD) and caspase-3 activities. In the group fed the highest level of n-3 HUFA, decreased percentages of major phospholipids (PL) in the mitochondrial and microsomal membranes of the liver were also apparent. The percentage of mitochondrial cardiolipin (Ptd(2)Gro) was 3.1 in the highest n-3 group compared to 6.6 in the intermediate group. These data clearly show an increased incidence of oxidative stress in the liver of fish fed the high n-3 diets.
authors.affiliation: Nofima, NO-1432, As, Norway. marte.kjaer@nofima.no
authors.forename: M A
authors.initials: MA
authors.lastname: Kjaer
authors.forename: M
authors.initials: M
authors.lastname: Todorcević
authors.forename: B E
authors.initials: BE
authors.lastname: Torstensen
authors.forename: A
authors.initials: A
authors.lastname: Vegusdal
authors.forename: B
authors.initials: B
authors.lastname: Ruyter
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000494:pharmacology*; D008099:Liver / Q000737:chemistry; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D020317:Salmo salar; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D013482:Superoxide Dismutase; D053148:Caspase 3