Fig. 4

Time profiles of serum concentration of allopurinol and oxypurinol. Crl:CD and Jcl:SD rats were administered allopurinol (30 mg/kg): a-d or (100 mg/kg): e-h. Each point represents the mean ± standard deviation (SD) of three experiments. a Serum allopurinol concentration in vehicle-treated rats. b Serum oxypurinol concentration in vehicle-treated rats. c Serum concentration of allopurinol in rats treated with febuxostat (10 mg/kg) for 5 days. d Serum concentration of oxypurinol in rats treated with febuxostat (10 mg/kg) for 5 days. e Serum concentrations of allopurinol in vehicle-treated rats. f Serum oxypurinol concentrations in vehicle-treated rats. g Serum concentrations of allopurinol in rats treated with febuxostat (10 mg/kg) for 5 days. h Serum concentration of oxypurinol in rats treated with febuxostat (10 mg/kg) for 5 days