IL1B and endothelial dysfunction: On the other hand, no role for pro-inflammatory enzymes, such as COX or iNOS, was observed for the endothelial dysfunction evoked by IL-1β, as it was not modified by the inhibition of COX with indomethacin (10 μmol/L) (Figure 3D) or by the blockade of iNOS with 1400 W (10 μmol/L) (Figure 3E).