A: Example of overlapping immunostaining image for Von willebrand Factor (green arrow), α-actin (red arrow), Dapi (blue arrow), and over-lap between Von willebrand and α-actin (yellow arrow) in mouse hind-limb; B: Amplification of a portion from image A; C: Effect of sodium nitrite (SN) treatment on the capillary density in sham and hypertensive mice induced by chronic infusion of angiotensin II (Ang II) or L-NAME. Capillary density was assessed by von Willebrand immunostaining, n=5; *P < 0.05 for sham vs. L-NAME treatment and Ang II; #P < 0.05 for sham, L-NAME and Ang II treated with sodium nitrite vs. sham, L-NAME and Ang II.