CHEMISTRY OF URIC ACID
Humans excrete approximately 0.7 g uric acid daily. Most of this is derived from the metabolic breakdown of the purine bases adenine and guanine. Uric acid is less ionized and less water soluble at most acidic pH’s. It exists mostly as the monovalent salt sodium urate. However, uric acid itself may be the predominant form found in an acid urine. Because the urine becomes more acidic as it moves through the renal tubular system, fil-tered urate is increasingly converted to uric acid. The relatively limited solubility of urate at a urinary pH of 5 is clinically significant in patients with gout because of the possibility of the formation of uric acid stones.