EDN1 and endothelial dysfunction: Endothelial dysfunction may be a critical and initiating factor in the development of diabetic vascular disease.[1, 2] The broad definition of endothelial dysfunction, a systemic pathological state of the endothelium (the inner lining of the blood vessels), is an imbalance between endothelium-derived relaxing factors (EDRF) e.g. nitric oxide (NO), and prostacyclin and endothelium-derived constricting factors (EDCF) e.g. thromboxane A2 (TxA2), prostaglandin H2 (PGH2), endothelin-1 and angiotensin II.[3]