High n‐3 HUFA levels in the diet of Atlantic salmon affect muscle and mitochondrial membrane lipids and their susceptibility to oxidative stress |
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| Authors: | T‐K ØSTBYE MA KJÆR AMB RØRÅ B TORSTENSEN B RUYTER |
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| Institution: | 1. Nofima Marine, Norwegian Institute of Food, Fisheries and Aquaculture Research, ?s, Norway;2. Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, ?s, Norway;3. NIFES, National Institute of Nutrition and Seafood Research, Bergen, Norway |
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| Abstract: | Atlantic salmon were fed one of four diets with increasing levels (11–58%of total fatty acids (FAs)) of n‐3 highly unsaturated FAs (HUFAs) in order to investigate the effect on muscle and mitochondrial membrane lipids and their susceptibility to oxidative stress. The high n‐3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) groups contained lower percentages of sphingomyelin and cardiolipin in total muscle than the intermediate n‐3 HUFA group. Cardiolipin and sphingomyelin are particularly susceptible to peroxidation, and a reduced percentage of these lipids showed that mitochondrial membranes had been damaged by oxidation. The intermediate n‐3 HUFA group had the highest level of mitochondrial integrity and tendencies of lower thiobarbituric acid reactive substances (TBARS) level than the other dietary groups. The high caspase‐3 activity, in addition to casp3a and bax gene expression levels, in the n‐3 DHA group also suggests that some degree of oxidative stress had occurred. Electron microscopy images showed a higher degree of myofibre–myofibre detachment in fish fed the high HUFA diets than in fish fed the intermediate n‐3 HUFA diet. Our findings show that intermediate levels of n‐3 HUFAs in salmon diets gave the best protection against oxidative damage of mitochondrial membranes and muscle structure. |
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| Keywords: | Atlantic salmon docosahexaenoic acid eicosapentaenoic acid mitochondria muscle oxidative stress |
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