Glucuronic Acid as a Growth Factor in Guinea Pigs

Abstract

It is generally considered that the animal body can synthesize glucuronic acid either from carbohydrates or from amino acid metabolites. Miller and Conner have reported results previously which indicate that either the rabbit cannot synthesize glucuronic acid or that the rate of synthesis is low. A similar investigation on dogs did not give such definite indications. In comparing the chemical properties of glucuronic acid with the chemical properties of Vitamin C, we were struck with the close similarity existing between them. Svirbely and Szent-Györgyi 1 have reported evidence indicating that Vitamin C is an hexuronic acid. Glucuronic acid is an hexuronic acid and we decided to compare its biochemical properties with those of Vitamin C, even though Hirst and Reynolds 2 state that the hexuronic acid isolated by Svirbely and Szent-Györgyi is not glucuronic acid. We were interested also in the importance of glucuronic acid in growth.

If glucuronic acid cannot be synthesized by the growing animal, it would then be an essential carbohydrate acid for growth, for it is a constituent of the glycoproteins in cartilage, connective tissue and mucin. If glucuronic acid can be synthesized by the growing animal, then they should experience no difficulty in growth on a diet deficient in glucuronic acid.

Eighteen guinea pigs weighing 280-320 gm. were fed the basal Vitamin C deficient diet of Sherman, LaMer, and Campbell, 3 ad lib. Of these, 6 were fed, by dropper, a water solution containing 2 mg. of an equilibrium mixture of glucuronic acid∗ and its lactone, for 9 days, and thereafter 10 mg. per day. Six were fed 1/4 gm. of gastric mucin per day, mixed with dry feed, and 6 were kept as controls.