Fig. 6.
A: representative Western blot of endothelial NO synthase (eNOS) in single mesenteric arteries of 6- and 24 mo-old rats. GAPDH was used to normalize for loading variations. B: summary data of four Western blots. Data are normalized by means of densitometric ratios of eNOS and GAPDH from vessels of 6-mo-old rats. NS, not significant. C: basal activity of eNOS as determined by measuring the rate of conversion of l-[3H]citrulline from l-[3H]arginine in mesenteric arteries of 6- and 24-mo-old rats. D: perfusate nitrite in control (15 dyn/cm2 of shear stress) and in the presence of ACh (10–5 M) plus shear stress (15 dyn/cm2) in mesenteric arteries of 6- and 24 mo-old rats. *P < 0.05 vs. control; ≠P < 0.05 compared with corresponding data from 6-mo-old rats.