XDH and endothelial dysfunction: Indomethacin and allopurinol, a cyclooxygenase inhibitor and a xanthine oxidase inhibitor, respectively, did not improve EDR in the WTD-GS (+) group (Figs 4, S4A, S4B, S5A and S5B), suggesting that prostaglandins and xanthine oxidase-derived radicals are unlikely to be responsible for endothelial dysfunction.