부산대학교 도서관

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. [ABSTRACT FROM AUTHOR]