2.1. Chemicals and reagents
Xanthine, potassium oxonate, uric acid, probenecid, benzbromarone,
allopurinol and indomethacin were purchased from
Sigma-Aldrich (USA). Ketamine and xylasine was obtained from
Sespro Industria e Comercio Ltda (Brazil). Uric acid assay kit was
purchased from Bioclin (Brazil). Monosodium urate (MSU) crystals
were prepared according to previously described method (Rasool
and Varalakshmi, 2006). All other chemicals were the highest
analytic grade available.