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 investigated in juvenile lake sturgeon. Ten-month old lake sturgeon were fed diets supplemented with either 0 or 1250 mg ascorbic acid/kg diet concomitantly with either 0 or 200 mg α tocopherol/kg diet for 7 weeks at 17°C. Dietary vitamin C supplement resulted in significant increases of ascorbate concentrations in the posterior kidney and liver of sturgeon. Dietary vitamin E omission affected liver concentrations of α-tocopherol (10.0 ± 4.5 μg/g) in comparison to sturgeon fed a diet supplemented with vitamin E and vitamin C (99.5 ± 22.9 μg/g). Dietary vitamin C supplement decreased liver α-tocopherol concentration in vitamin E-deprived sturgeon. Also, vitamin E supplement lowered posterior kidney and liver ascorbic acid concentrations in vitamin C-deprived sturgeon. Gulonolactone oxidase and dehydroascorbic acid reductase activities were stimulated in groups fed vitamin C. Thiobarbituric acid-reactive substances concentrations (an indicator of lipid peroxidation) were higher in sturgeon fed either of vitamins as compared to sturgeon deprived of both vitamins. The results suggested that large doses of vitamins C and E may be prooxidant in vivo.