Figure 2. Mechanism of unoprostone isopropyl -mediated endothelium-dependent vasodilation. Role of the endothelium and endothelium-derived relaxing factors in retinal arteriolar dilation in response to unoprostone isopropyl (UI). The effects of endothelium removal, incubation with NG-nitro-L-arginine methyl ester (L-NAME) (10 µM, n = 4), indomethacin (10 µM, n = 4), sulfaphenazole (10 µM, n = 4), and CAY10441 (0.1 μM, n = 4). Incubation with L-NAME significantly reduced vasodilation in response to UI, which was comparable to that produced by denudation, but not indomethacin, sulfaphenazole, or CAY10441. *p<0.05 versus control.