Uric acid (UA) is an organic heterocyclic compound (C5H4N4O3) with a molecular weight of 168Da [1]. UA is a product of the metabolism of purines such as adenosine and guanosine. Many enzymes are involved in this pathway. Hypoxanthine is oxidated to xanthine and then to UA by the enzyme xanthine oxidase. In most mammals and vertebrates, UA degrades further to allantoin by urate oxidase (uricase). The lack of uricase in humans and the significant reabsorption of UA lead to serum UA levels that are 10-fold higher than in most mammals and vertebrates.
