Synthesis of Dehydroascorbic Acid by Subadult Lobsters (Homarus americanus)

Using radiotracer studies we assessed the ability of lobsters (Homarus americanus) (200–300 g) to synthesize ascorbic acid from [14C]glucose. No deficiency symptoms were observed in groups of 15 lobsters fed one of three semipurified diets containing 0, 1.2, and 6 g ascorbic acid/kg (diets 1, 2, and 3, respectively) for 14 wk. Six of the animals on diet 1 were studied in vivo. Five intermolt lobsters were selected from each dietary group for an in vitro study. Lobsters synthesized dehyroascorbic acid in the hepatopancreas from [14C]glucose. Dietary level of ascorbic acid had no significant effect on the amount of [14C]dehydroascorbic acid detected. We consider that the rate of synthesis and degradation may be affected by the molt cycle.