Ascorbic acid metabolism in adrenalectomized rats

Male albino rats were adrenalectomized and their ascorbic acid, dehydroascorbic acid, and diketogulonic acid were determined in liver and urine, while only the total ascorbic acid was determined in blood, at the intervals of 4, 8, and 12 days after adrenalectomy. Activities of ascorbic acid synthesizing enzyme d-glucurono-δ-lactone hydrolase, l-gulono-γ-lactone hydrolase, and l-gulono-γ-lactone oxidase were estimated in liver. The activities of ascorbic acid degrading enzymes dehydroascorbatase and 2,3 diketoaldonate decarbozylase were studied in liver and kidney. In adrenalectomized rats there was a slight decrease in the ascorbic acid level and an appreciable decrease in dehydroascorbic acid content of the liver. On the other hand, there was about two-fold increase in the diketogulonic acid content of liver. The content of ascorbic acid and dehydroascorbic acid in the urine of adrenalectomized rats decreased significantly, while there was slight increase in the diketogulonic acid content. There was also a slight decrease in total ascorbic acid content of blood. Decreases of about 20% and 30% were observed in the activities of d-glucurono-δ-lactone hydrolase and l-gulono-γ-lactone oxidase respectively, while the activity of l-gulono-γ-lactone hydrolase remained practically unchanged. An appreciable increase in the activity of dehydroascorbatase and a moderate increase in the activity of diketoaldonate decarboxylase were observed in liver and kidney of adrenalectomized rats. All corresponding alterations were more conspicuous in rats 12 days after adrenalectomy.