Relative importance of liver and kidney in synthesis of uric acid in chickens

Broiler chickens of 1, 2, and 7 months of age were used for enzymatic spectrophotometric determination of uric acid and its precursors, xanthine, hypoxanthine, and inosinic acid, in the liver and kidney in an attempt to show the relative importance of the two organs in the synthesis of uric acid, the major nitrogenous compound excreted by birds.Uric acid concentration of the kidney was two to three times as high as the liver, probably attributable in part to preformed uric acid trapped in the urinary passages in the kidney. Significantly higher concentrations of xanthine, hypoxanthine, and inosinic acid were found in the kidney than in the liver. The calculations based on organ weight and the concentrations of uric acid precursors suggest that the kidney synthesizes 96, 60, and 73% as much uric acid as does the liver for the 1-, 2-, and 7-month-old chickens, respectively.