EDN1 and diabetic kidney disease: Increased mRNA expression of ET-1 and ETAR in gddY mice in this study suggests that the endothelin system is upregulated in experimental IgAN in accordance with clinical findings, including the increased staining for ET-1 in endothelial cells of glomerular and peritubular capillaries reported in patients with IgAN or diabetic nephropathy compared with healthy patients [30].