Carotid artery compliance and systemic nitric oxide synthase inhibition in young healthy adults

Abstract

Decreased arterial compliance (increased arterial stiffness) is associated with cardiovascular events. Nitric oxide regulates vascular tone, which can influence arterial compliance. We previously investigated the effects of systemic NOS inhibition on arterial compliance under the systemic α‐adrenergic receptor blocking. In the present study, we investigated the effect of systemic NOS inhibition alone on central arterial compliance. Sixteen apparently healthy young adults (26±1 years) underwent intravenous infusions of NG‐monomethyl‐L‐arginine (L‐NMMA) or placebo (saline) on separate days. In the placebo control condition, no significant changes were observed in mean arterial pressure (68±2 vs. 71±1 mmHg), carotid artery compliance (0.10±0.01 vs. 0.10±0.01 mm2/mmHg), and β‐stiffness index (7.3±0.3 vs. 7.1±0.4 AU). After the administration of L‐NMMA, mean arterial pressure increased significantly (70±2 vs. 79±2 mmHg). However, there were no significant changes in carotid artery compliance (0.09±0.01 vs. 0.10±0.01 mm2/mmHg) or carotid β‐stiffness index (7.3±0.3 vs. 6.7±0.4 AU), an index adjusted for distending pressure. Our findings indicate that systemic NO inhibition does not modulate central arterial compliance in young healthy adults.