Egan B, Schork N, Panis R, Hinderliter A
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor 48109-0356.
J Hypertens. 1988 Jan;6(1):41-8.
Forearm blood flow (FABF) and forearm vascular resistance (FAVR) responses to sequential regional infusions of norepinephrine (NE) and angiotensin II (Ang II) were examined in 24 hypertensive and 18 matched normotensive subjects. Sensitivity to both vasoconstrictors, defined as the percentage increase in FAVR in response to the lowest dose of each agonist, was similar in the two groups. Also, the FABF response curve to the full range of both agonists did not differ between hypertensives and normotensives by analysis of variance (ANOVA). While the FAVR responses at the lowest doses of both NE and Ang II were similar in hypertensives and normotensives, FAVR responses in hypertensives diverged progressively from the normotensive response pattern, P less than 0.01 according to ANOVA. The hypertensives achieved greater maximum FAVR levels at the highest doses of both agonists, P less than 0.05 according to repeated measures ANOVA. After 10 min of ischaemic exercise, FAVR was higher in hypertensives than in normotensives (2.24 +/- 0.10 versus 1.87 +/- 0.08; P = 0.02, respectively). This value for FAVR was termed the minimum FAVR (mFAVR). The overall response pattern characterized by increased mFAVR, unchanged threshold sensitivity, steeper slope, greater maximum response and similarity of responses to both NE and Ang II is most consistent with a structural augmentation of resistance responses. A model was used in an effort to increase understanding of the vessel morphology. This model suggested that an increased wall/lumen ratio, perhaps without an actual increase in vascular smooth muscle mass, played an important role in the observed FAVR pattern.
在24名高血压患者和18名匹配的正常血压受试者中，研究了前臂血流量（FABF）和前臂血管阻力（FAVR）对去甲肾上腺素（NE）和血管紧张素II（Ang II）连续区域输注的反应。两组对两种血管收缩剂的敏感性（定义为每种激动剂最低剂量引起的FAVR百分比增加）相似。此外，通过方差分析（ANOVA），高血压患者和正常血压患者对两种激动剂全剂量范围的FABF反应曲线没有差异。虽然高血压患者和正常血压患者在NE和Ang II最低剂量时的FAVR反应相似，但高血压患者的FAVR反应逐渐偏离正常血压反应模式，根据ANOVA，P<0.01。在两种激动剂的最高剂量时，高血压患者达到了更高的最大FAVR水平，根据重复测量ANOVA，P<0.05。缺血运动10分钟后，高血压患者的FAVR高于正常血压患者（分别为2.24±0.10和1.87±0.08；P = 0.02）。这个FAVR值被称为最小FAVR（mFAVR）。以mFAVR增加、阈值敏感性不变、斜率更陡、最大反应更大以及对NE和Ang II反应相似为特征的总体反应模式与阻力反应的结构增强最为一致。使用了一个模型来努力增加对血管形态的理解。该模型表明，壁/腔比值增加，可能没有血管平滑肌质量的实际增加，在观察到的FAVR模式中起重要作用。
