NOS3 and liver dysplastic nodule: Further, a triphasic response of increased, unaltered, and impaired endothelial NO-dependent vascular relaxation within the same diabetic animal [16] and the downregulation of glomerular or renal eNOS expression in progressive models of DN (OVE26 mouse, ZSF1 rat) [17, 18] suggested that eNOS-mediated NO production is decreased during the progression of DN.