The effects of allopurinol, uric acid sodium salt, and inosine on plasma uric acid and xanthine oxidase activity in broilers

Xanthine oxidoreductase (XOR) has two forms in the avian, xanthine dehydrogenase (XD) and xanthine oxidase (XO). The purpose of these studies was to determine the effects of allopurinol and inosine on plasma uric acid and enzyme activity. In the first study, Cobb × Cobb (n=25; 7 weeks old) broilers were assigned to five treatments (n=5). Treatments included: Group 1 (control, no allopurinol), Group 2 (allopurinol addition), Group 3(allopurinol and osmotic pump), Group 4 (allopurinol, dietary uric acid addition), and Group 5 (allopurinol, uric acid injection). PUA was measured before the addition of allopurinol and weekly after the onset of the 3 week study. Total XO+XD in the liver was significantly higher (p=0.012) in group1 as compared to group 3 birds. Birds in group 2, group 4, and group 5 had significantly lower (p≤ 0.001) uric acid concentrations in the liver. In the second study, Cobb × Cobb (n=15; 5 weeks old) were separated into three treatments (n=5); control (CON), INO (inosine at 161g/kg feed), or INOAL ( inosine and allopurinol 50mg/kgBW). There was a significant increase (p=0.005) in total enzyme activity of the liver in the INO birds. INOAL birds had a significantly lower (p=0.005) uric acid concentration in the liver. The reduced uric acid concentration in the liver suggests that there is a residual effect of allopurinol, which potentially results in lowered antioxidant activity in this tissue.