Vitamin C and the Adrenal Gland in the Dog. ∗

Abstract

Conclusion

No evidence has been obtained that the adrenal gland, as an organ in the dog, is concerned with either the synthesis or the metabolism of vitamin C. If the adrenals do play any role in the metabolism of this compound the action is conferred by the adrenal cortical hormone.

Harris and collaborators 1 , 2 have shown that dogs do not require vitamin C in their diets for adequate nutrition. Others have kept dogs upon synthetic rations, presumably devoid of this vitamin, for periods of 1-4 years without symptoms of scurvy. Tissues from such animals, notably the adrenals and liver, show by chemical and biological tests the presence of large amounts of ascorbic acid. Similar tissues from guinea pigs kept upon scorbutic diets reveal a marked diminution in the content of ascorbic acid as scurvy develops.

The early observation 3 that the cortex of the adrenal gland contained large amounts of “hexuronic acid”, later shown to be vitamin C 4 , 5 , 6 has led to speculation upon the relationship of this vitamin to the functions of the adrenal cortex. The belief that the medulla 7 did not contain “hexuronic acid” supported the idea of a functional significance for this uneven distribution. It has since been demonstrated that other animal tissues contain appreciable amounts of ascorbic acid, e. g., liver, 8 corpora lutea, 9 , 10 pituitary 11 thymus. 12 Huszák 13 has shown that the adrenal medulla contains as much vitamin C as does the cortex. Such a wide distribution is hardly indicative of a specific relationship between vitamin C and the functions of the adrenal cortex. In those species that do not develop scurvy one may reasonably consider any tissue containing much vitamin C as having a possible rôle in protecting the animal from this nutritional disorder.

The question arises, is the adrenal gland in the dog concerned specifically with the synthesis and metabolic functioning of vitamin C and the consequent protection of the animal from scurvy?