Potassium oxonate

Potassium oxonate is an inhibitor of uricase, inhibits the phosphorylation of 5-FU to 5-fluorouridine-5'-monophosphate catalyzed by pyrimidine phosphoribosyl-transferase in a different manner from allopurinol in cell-free extracts and intact cells in vitro. IC50 value: Target: On p.o. administration of 5-FU (2 mg/kg) and a potent inhibitor of 5-FU degradation to Yoshida sarcoma-bearing rats, oxonic acid (10 mg/kg) was found to inhibit the formation of 5-fluorouridine-5'-monophosphate from 5-FU and its subsequent incorporation into the RNA fractions of small and large intestine but not of tumor and bone marrow tissues [1]. Oxonic acid diet increased plasma uric acid by 80-90 micromol/l, while blood pressure was elevated only in hyperuricemic 5/6 nephrectomy rats (18 mmHg) [2].