Skip to main content
. Author manuscript; available in PMC: 2012 Jul 1.
Published in final edited form as: Free Radic Biol Med. 2011 Apr 15;51(1):179–184. doi: 10.1016/j.freeradbiomed.2011.04.004

Fig. 5. Febuxostat is superior to allo/oxypurinol at inhibiting endothelial cell-bound XO.

Fig. 5

A) BAECs were exposed to purified XO (5 mU/ml) for 20 min 25°C and washed as described in the methods. Inhibitors were added at the indicated concentrations followed by xanthine (100 μM) and uric acid levels assessed after 1 h. Values represent % control (no inhibitor) and are the mean of at least 3 independent determinations (* = p < 0.05). B) Purified XO was bound to BAEC GAGs (as in A), the cells were then harvested by mechanical dissociation and resuspended at 1 × 106 cells/ml. Cell suspensions were exposed to the indicated concentrations of inhibitor followed by xanthine (100 μM) and immediately analyzed by EPR spin trapping of extracellular O2 •- with PPH (50 μM). Spectra represent XO-loaded cells exposed to PPH and the following agents from top to bottom: (- xanthine), (+ xanthine), (+ xanthine and SOD), (100 U/ml), (XO-loaded cells treated with trypsin to remove extracellular XO and then exposed to xanthine), (+ xanthine and 50, 100 or 200 μM allopurinol), (+ xanthine and 10, 25 and 50 nM febuxostat). Each spectrum represents 5 cumulative scans over 1 min from t = 9-10 min at 37°C and 21% O2.