NOS3 and diabetes mellitus: eNOS was shown to be the major NOS enzyme in renal vasculature [6–8], and eNOS expression was shown to be upregulated in early (1–6 weeks) diabetic kidneys, especially in afferent and glomerular endothelium, concomitant with increases in diameter of afferent arterioles, glomerular volume and filtration rate, and urinary NO metabolites (NOx) [9–11].