Dietary (n-3) fatty acids increase superoxide dismutase activity and decrease thromboxane production in the rat heart.
1997
Luostarinen R. | Wallin R. | Saldeen T.
The aims of the present studies were to examine the effects of fish oil (containing (n3) polyunsaturated fatty acids) on myocardial thromboxane and prostacyclin production, superoxide dismutase (SOD) activity and malondialdehyde (MDA) production in the rat. Male rats were fed standard pellet diets and the same diets enriched with 7% (w/w) stabilized fish oil or 7% butter (saturated fat) for 2-6 wk. Myocardial production of thromboxane was lower in rats given fish oil than in those fed standard pellets (P < 0.01) or saturated fat (P < 0.05) and the prostacyclin/ thromboxane ratio was higher than in rats fed standard pellets (P < 0.05). Myocardial SOD activity was higher in rats fed stabilized fish oil than in those given saturated fat (P < 0.05). Supplementation of the stabilized fish oil with extra vitamin E did not have any major effect on thromboxane and prostacyclin production or SOD activity. The percentage of arachidonic acid in the myocardial phospholipids was lower (P < 0.001) during fish oil than during saturated fat feeding, with no modifying effect of vitamin E supplementation. Feeding with the stabilized fish oil did not alter the myocardial alpha-tocopherol concentration, but the myocardial MDA concentration in vitro was higher (P < 0.01) than after feeding with saturated fat. Supplementation of the stabilized fish oil with extra vitamin E resulted in a higher alpha-tocopherol (P < 0.05) and lower MDA concentration (P < 0.05) in the myocardium compared to the unsupplemented fish oil. Plasma MDA concentration was not changed by fish oil feeding. In conclusion, fish oil feeding resulted in higher myocardial SOD activity and lower thromboxane production. These changes may be contributory mechanisms underlying the antiarrhythmic effect of fish oil.
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