Lipid peroxidation and antioxidant status is affected by different vitamin E levels when feeding fish oil.

The protective role of vitamin E and changes in the status of several physiological antioxidants after feeding rats a fish oil diet were investigated. Six-week-old male Sprague-Dawley rats were divided into four groups and fed experimental diets for 8 wk. Three fish oil (FO) groups were fed a menhaden fish oil and soybean oil (SO) (9:1) mixture as 10% (w/w) of the diet. These groups were provided with < or = 3, 45 or 209 IU of vitamin E/kg diet. One SO group was used as control and was fed < or = 45 IU of vitamin E/kg diet. Plasma vitamin E levels, when expressed as vitamin E per mL plasma, were extremely low in the group fed FO and < or = 3 IU of vitamin E, and were lower in the groups fed FO than in the group fed SO. However, plasma vitamin E levels when expressed per mg plasma lipid were higher in the FO groups provided with < or = 45 and 209 IU of vitamin E than in the SO group. Compared with the SO group, plasma levels of thiobarbituric acid reactive substances (TBARS), when expressed per mg lipid, were higher in the three FO groups, plasma retinol levels were lower in the FO groups provided with < or = 3 and 45 IU of vitamin E, and ascorbic acid levels were lower only in the FO group provided with < or = 3 IU of vitamin E. Blood glutathione (GSH) levels were lower in all three FO groups than in the SO group.(ABSTRACT TRUNCATED AT 250 WORDS)