Effect of hydrocortisone on the metabolism of L-ascorbic acid in rats

Adrenalectomy causes a significant decrease in the tissue levels of l-ascorbic acid. The ascorbic acid concentration is raised when adrenalectomized animals receive hydrocortisone. Various enzymes of l-ascorbic acid metabolism have been measured in rats after adrenalectomy and subsequent treatment with hydrocortisone and/or actinomycin D. Hydrocortisone stimulates the activity of liver gulono-oxidase responsible for the synthesis of l-ascorbic acid from l-gulonolactone. A slight increase in the activity of dehydroascorbatase is also observed in the adrenalectomized rats. Little change was observed in uronolactonase, l-gulonate dehydrogenase and l-gulonate decarboxylase activities.