In humans, endothelial vasodilator function serves as a surrogate marker for cardiovascular health and is measured as changes in conduit artery diameter after temporary ischemia (flow-mediated dilation; FMD). Here, we present an FMD-related approach to study femoral artery (FA) vasodilation in anesthetized rats. Diameter and Doppler-flow were monitored in the FA. Using high-resolution ultrasound (35 MHz) and automated analysis software, we detected dose-dependent vasodilation using established endothelium-independent (IV nitroglycerin EC₅₀=3.3x10^-6 mol/L, peak 21% (SD 4)) and endothelium-dependent (IA acetylcholine EC₅₀=1.3x10^-6 mol/L, peak 27% (SD 4)) pharmacologic vasodilators. Wall shear stress (WSS) induced by intra-aortic injection of adenosine and infusion of saline at increasing rates (1.5-4.5 mL/min) led to vasodilation at 1-2 min. Transient hindlimb ischemia by common iliac occlusion (5 min) led to reactive hyperemia with flow-velocity and WSS increase and was followed by FA dilation (16% (SD 2)), the latter of which was completely abolished by NO-synthase (NOS) inhibition with L-NMMA (1% (SD 2)). FMD was significantly reduced in adult 20-24 week old animals as compared to 9-10 week old animals, consistent with age-dependent endothelial dysfunction (16% (SD 3) vs 10% (SD 3), p<0.05). While FMD was completely NOS-dependent in 9-10 week old animals, NOS-dependent mechanisms accounted for only half of the FMD in 20-24 week old animals, with the remainder being blocked by charybdotoxin and apamin, suggesting contribution of endothelium-derived-hyperpolarizing-factor. To our knowledge, this is the first integrative physiologic model to reproducibly study FMD of conduit arteries in living rats.