Department of Clinical Research and Human Physiology, Semmelweis University, Budapest, Hungary.
Kidney Blood Press Res. 2010;33(1):37-47. doi: 10.1159/000285847. Epub 2010 Feb 23.
BACKGROUND/AIMS: To identify the relationship between systemic and local hemodynamics, as well as segmental biomechanical properties in a musculocutaneous resistance artery during angiotensin-II hypertension and its recovery.
Rats were infused with angiotensin-II using implanted osmotic minipumps (ALZET 2ML4, 150 ng/kg/min) for 4 weeks. Measurements were made either immediately following infusion or after an additional 4-week recovery period. Parallel controls were created. Segmental geometry and blood flow were determined in vivo on microsurgically exposed segments of the saphenous arterial branch (350 mum). Pressure-radius plots of excised cylindrical segments were recorded by pressure arteriography.
Eutrophic hypertensive wall remodeling developed, with reduced passive radius, increased wall thickness, elevated low-stress elastic modulus, reduced norepinephrine contraction, and reduced endothelium-mediated dilation. Relaxed wall geometry fully healed in 4 weeks of recovery, but an increased contractility and a reduced in vivo lumen persisted. Regional hemodynamic resistance correlated positively with systemic arterial pressure and wall thickness in vivo, and negatively with in vivo lumen size throughout these studies.
A partial recovery of the biomechanical parameters was found. Healing of eutrophic hypertensive remodeling of the resistance artery wall is a complex biomechanical process, not a simple reversal of the original pathological sequel.
背景/目的：在血管紧张素-Ⅱ高血压及其恢复期间，确定肌皮阻力动脉的全身和局部血液动力学以及节段生物力学特性之间的关系。
通过植入的渗透微型泵（ALZET 2ML4，150ng/kg/min）向大鼠输注血管紧张素-Ⅱ，持续 4 周。输注后立即或再经过 4 周恢复期进行测量。创建平行对照。在微外科暴露的隐动脉分支（350µm）的体内对节段几何形状和血流进行了测量。通过压力血管造影术记录离体圆柱形节段的压力-半径图。
发生了营养性高血压性壁重构，表现为被动半径减小、壁厚度增加、低应变成弹性模量升高、去甲肾上腺素收缩减少以及内皮介导的扩张减少。在 4 周的恢复期内，松弛的壁几何形状完全愈合，但收缩性增加和体内管腔减小持续存在。局部血液动力学阻力与体内动脉血压和壁厚度呈正相关，与这些研究中体内管腔大小呈负相关。
发现生物力学参数有部分恢复。阻力动脉壁的营养性高血压性重构的愈合是一个复杂的生物力学过程，而不是对原始病理后果的简单逆转。
