High steady-state levels of uric acid produced in rats by dietary training and potassium oxonate.

To reduce the inherent variability in serum uric acid levels of animals allowed ad libitum exposure to food containing potassium oxonate and uric acid, male Sprague-Dawley rats were trained to eat their daily food allotment in a 1.25-hr period each morning. After training the rats were fed a food mixture containing 5% potassium oxonate and 2% uric acid (w/w each). Serum blood levels of uric acid reached a steady state within 2 hr; these levels were maintained for an additional 4 hr. It is believed that the stomach emptying rate is a zero-order process under these experimental conditions.