Fixation of Ascorbic Acid by Tissues

Abstract

During the last few years considerable data have been accumulated to show that scorbutic animals suffer a marked depletion of the ascorbic acid content of the tissues particularly in organs such as the adrenal, pituitary, intestine, and liver. This depletion is readily made up when vitamin C rich foods are fed to the animals. The importance of the presence of ascorbic acid has been subsequently linked up with its function as an oxygen carrier, particularly through the studies of Harrison and Euler and Klussmann. They showed that tissue slices from scorbutic animals have a low oxygen uptake which is restored by the addition of ascorbic acid. Söderström and Törnblom further show that in scorbutic animals the oxygen consumption is diminished. The ability of tissues to fix ascorbic acid was suggested by the report of Harris, Ray and Ward.. They believed from their study of the urinary output of vitamin C that the amount excreted might serve as a gauge of the nutritional state of the individual. This suggests that the tissues must be saturated with ascorbic acid before it will overflow through the kidney. This conception is supported by further observations of Harris and Ray, Johnson and Zilva, Ippen, Euler and Malmberg, Hou and others on the urinary excretion of ascorbic acid in man and animals, in various nutritional states and following the administration of ascorbic acid orally or intravenously. Zilva found a marked increase in the ascorbic acid content of the intestine of scorbutic animals after the injection of ascorbic acid. He further showed that the antiscorbutic activity of the ascorbic acid and its related compounds appeared to be “connected with their capacity of being retained by the tissues of the animal organism.” By means of histological staining with AgNO3 Giroud and coworkers were able to trace the deposition of ascorbic acid in the intestine, the blood, the liver and kidney, after orange juice was given to scorbutic animals. De Caro studied the ascorbic acid content of the organs of normal and scorbutic guinea pigs at different periods following the intravenous injection of ascorbic acid and found a transient rise in normal animals. The concentration in the kidney and muscles of the scorbutic animals reached normal or even above normal in 15 minutes; other organs showed an increase although they did not reach a normal value. He further studied the effect of ascorbic acid solutions in contact with tissue emulsions and concluded that the behavior of the normal and scorbutic tissue emulsions was essentially the same. The slight difference obtained was considered to be due to loss in filtration and to the amount of ascorbic acid present in the tissue. De Caro thus believed that in scorbutic animals the ability of the tissue to fix ascorbic acid was decreased.