There is, perhaps, no nitrogenous substance in the urine that has been more carefully studied than uric acid. The majority of the investigations concerning the uric acid content of the urine which have been carried out have dealt chiefly with adults. The present report is of a study of the uric acid metabolism in children.
It was believed for a long time that uric acid in mammalian urine was an intermediary product of protein metabolism which was almost completely oxidized by the body to urea. We now know that this point of view is fundamentally incorrect, and that uric acid is derived from the catabolism of the nucleins of both the food and the tissues. As is well known, the nucleins contain nucleic acid, which in turn contains purins. It is the oxidation of the purins that yields uric acid.
The variations in the total daily elimination of uric acid,
LEOPOLD JS, BERNHARD A, JACOBI HG. STUDIES IN THE URIC ACID METABOLISM OF CHILDREN. Am J Dis Child. 1924;27(3):243-255. doi:10.1001/archpedi.1924.01920090048006