Muntinga J H, van Leeuwen J T, Gels M E, Terpstra W F, Smit A J, Visser K R
Department of Medical Physiology, University of Groningen, The Netherlands.
J Hypertens. 1997 Apr;15(4):411-9. doi: 10.1097/00004872-199715040-00012.
To investigate differences between in-vivo properties of a vascular bed in hypertensive patients and normotensive controls.
Despite the controversy about the origin of essential hypertension and its accompanying vascular changes, it is generally assumed that the characteristic increase in peripheral resistance when hypertension progresses is caused by arteriolar constriction. Yet, there is little experimental evidence that this assumption generally holds in vivo.
A non-invasive technique was used for studying properties of the complete vascular bed of an upper arm segment under an occluding cuff in 23 previously untreated hypertensive patients and their matched normotensive controls. The method used the segment's electrical impedance to assess the volumes of extravascular fluid and of arterial and venous blood under varying arterial transmural pressures.
Compared with that of matched normotensive controls, the compliance of the large arteries of the vascular bed was on average 50.9% lower (P < 0.001) in the hypertensive patients. The compliance of the complete arterial bed at the operating blood pressure level was also lower (40.0%, P < 0.01), but appeared to be significantly higher (45.9%, P < 0.05) at the normotensive blood pressure level. On the venous side, the patients had a higher blood volume (60.0%, P < 0.01) and an increased myogenic response (68.5%, P < 0.05).
The increase in vascular resistance in the hypertensive patients is due primarily to changes in the large and small vessels of the arterial bed. We found no evidence for a generally increased arteriolar constriction.
研究高血压患者与血压正常对照组血管床的体内特性差异。
尽管原发性高血压的起源及其伴随的血管变化存在争议，但一般认为高血压进展时外周阻力的特征性增加是由小动脉收缩引起的。然而，几乎没有实验证据表明这一假设在体内普遍成立。
采用一种非侵入性技术，研究23例未经治疗的高血压患者及其匹配的血压正常对照组在上臂段袖带阻断下整个血管床的特性。该方法利用该段的电阻抗来评估不同动脉跨壁压力下血管外液以及动脉血和静脉血的容量。
与匹配的血压正常对照组相比，高血压患者血管床大动脉的顺应性平均降低50.9%（P < 0.001）。在工作血压水平时，整个动脉床的顺应性也较低（40.0%，P < 0.01），但在血压正常水平时似乎显著较高（45.9%，P < 0.05）。在静脉方面，患者的血容量较高（60.0%，P < 0.01），肌源性反应增强（68.5%，P < 0.05）。
高血压患者血管阻力的增加主要归因于动脉床大、小血管的变化。我们没有发现普遍存在小动脉收缩增加的证据。
