EDN1 and diabetes mellitus: ET-1 is synthesized from its inactive precursor by endothelin-converting enzyme-1 (ECE-1), making the ECE-1/ET-1 axis a central regulator of vascular tone, endothelial homeostasis, and inflammation (7, 8).Increasing evidence has implicated ET-1 in microvascular damage associated with diabetes, hypertension, and atherosclerosis.