Sugawara J, Saito Y, Maeda S, Yoshizawa M, Komine H, Nakamura M, Ajisaka R, Tanaka H
1] Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan [2] Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.
Graduate School of Comprehensive Human Sciences, The University of Tsukuba, Tsukuba, Japan.
J Hum Hypertens. 2014 Aug;28(8):494-9. doi: 10.1038/jhh.2013.137. Epub 2014 Jan 9.
Proximal large elastic arteries (ascending aorta and carotid artery) have an important role in buffering the pulsatile pressure generated from the left ventricle, which forwards continuous peripheral blood flow and protects the brain microcirculation from end-organ damage. Although compliance of distal conduit arteries (extremities' arteries) is attenuated by the nitric oxide synthase (NOS) inhibition, it is yet unknown whether compliance of proximal elastic arteries changes by the systemic NOS inhibition. To address this question, we measured central artery compliance in 17 young adults (26±1 years) who underwent intravenous infusions of N(G)-monomethyl-L-arginine (L-NMMA) or saline (placebo) on separate days. Following the systemic NOS inhibition, the mean arterial pressure (MAP), total peripheral resistance and aortic augmentation index were significantly increased. However, carotid artery compliance was not affected significantly (from 0.10±0.01 to 0.11±0.01 mm2) per mmHg) and the β-stiffness index (an index of arterial compliance adjusted for the distending pressure) tended to decrease (from 6.63±0.35 to 6.06±0.42 a.u., P=0.07). These parameters were not altered with saline infusion. Changes in the β-stiffness index tended to correlate negatively with the corresponding changes in MAP (r = -0.31, P=0.07). These results suggest that carotid artery compliance remains unchanged during the systemic NOS inhibition in spite of systemic vasoconstriction.
近端大弹性动脉（升主动脉和颈动脉）在缓冲左心室产生的脉动压力方面起着重要作用，这种脉动压力可促进外周血液的持续流动，并保护脑微循环免受终末器官损伤。尽管远端导管动脉（四肢动脉）的顺应性会因一氧化氮合酶（NOS）抑制而减弱，但目前尚不清楚全身NOS抑制是否会改变近端弹性动脉的顺应性。为了解决这个问题，我们对17名年轻成年人（26±1岁）进行了研究，他们在不同日期分别接受了静脉输注N（G）-单甲基-L-精氨酸（L-NMMA）或生理盐水（安慰剂）。在全身NOS抑制后，平均动脉压（MAP）、总外周阻力和主动脉增强指数显著升高。然而，颈动脉顺应性未受到显著影响（从0.10±0.01至0.11±0.01 mm2/mmHg），β硬度指数（一种根据扩张压力调整的动脉顺应性指数）有下降趋势（从6.63±0.35至6.06±0.42 a.u.，P=0.07）。输注生理盐水后这些参数未发生改变。β硬度指数的变化与MAP的相应变化呈负相关趋势（r = -0.31，P=0.07）。这些结果表明，尽管存在全身血管收缩，但在全身NOS抑制期间颈动脉顺应性保持不变。
