Vitamin C vitamin E interaction in juvenile lake sturgeon (Acipenser fulvescens R.), a fish able to synthesize ascorbic acid

The hypothesis that vitamin C interacts with vitamin E in vivo was investig ated in juvenile lake sturgeon. Ten-month old lake sturgeon were fed diets supplemented with either 0 or 1250 mg ascorbic acid/kg diet concomitantly w ith either 0 or 200 mg alpha-tocopherol/kg diet for 7 weeks at 17 degrees C . Dietary vitamin C supplement resulted in significant increases of ascorba te concentrations in the posterior kidney and liver of sturgeon. Dietary vi tamin E omission affected liver concentrations of alpha-tocopherol (10.0 +/ - 4.5 mu g/g) in comparison to sturgeon fed a diet supplemented with vitami n E and vitamin C (99.5 +/- 22.9 mu g/g). Dietary vitamin C supplement decr eased liver alpha-tocopherol concentration in vitamin E-deprived sturgeon. Also, vitamin E supplement lowered posterior kidney and fiver ascorbic acid concentrations in vitamin C-deprived sturgeon. Gulonolactone oxidase and d ehydroascorbic acid reductase activities were stimulated in groups fed vita min C. Thiobarbituric acid-reactive substances concentrations (an indicator of lipid peroxidation) were higher in sturgeon fed either of vitamins as c ompared to sturgeon deprived of both vitamins. The results suggested that l arge doses of vitamins C and E may be prooxidant in vivo.