B029: Intravenous infusion of L-NAME does not alter brachial artery area or compliance

Systemic administration of nitric oxide synthase (NOS) inhibitors increases blood pressure, in part due to inhibition of endothelium-dependent vasodilation at the resistance vessels. The effect of intravenous NOS inhibition on conduit vessels at a dose large enough to raise blood pressure has not been well defined. 7 young, healthy volunteers received intravenous infusion of NG-nitro-1-arginine methyl ester (L-NAME, 1.5 to 5.0 mg/kg). Brachial artery area was measured using a non-invasive echo-tracking system. A pressure waveform was acquired using tonometry at the radial artery and calibrated using a normal blood pressure cuff on the contralateral arm. Pressure-Area (P-A) and Pressure-Compliance (P-C) curves for the brachial artery were generated at baseline and over a 6-hour observation period post-infusion. Systolic (114 to 125 mm Hg, P