In the initial phase, an ameroid occluder (I.D. 2 to 2.5 mm, Research Instruments SW, Escondido, California) was placed on the proximal left circumflex coronary artery (LCX). Three weeks later, the animals were brought back for cardiac catheterization using a standard femoral access. A second 8F sheath (Avanti, Cordis, Miami, Florida) was introduced in the right femoral vein for atrial pacing. Heparin 100 U/kg was used for systemic anticoagulation. Intra-arterial pressure and electrocardiogram were continuously monitored and recorded. Selective angiography of the left and right coronary arteries was performed to confirm closure of the ameroid and to assess baseline angiographic parameters. Baseline regional blood flow was measured by intra-atrial colored microspheres. Two-dimensional echocardiographic recording was obtained at rest and after 2 min of atrial pacing at 170 beats/min to quantify global and regional cardiac function. Following these studies, the animals were randomly assigned to one of the following five groups (n = 8–9 for each group): 1) controls (saline infusion with IV 40 U/kg heparin bolus), 2) IV rhVEGF165 infusion 0.25 μg/kg/min, 3) IV rhVEGF165 infusion 0.05 μg/kg/min for 200 min, 4) IC rhVEGF165 infusion 0.25 μg/kg/min and 5) IC rhVEGF165 infusion 0.25 μg/kg/min, after 10 mg/kg IV bolus of L-NAME (Sigma, St Louis, Missouri). Except for group 3, infusions lasted for 40 min. Hemodynamic parameters were recorded for 40 min following the completion of infusion.