权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Measurement of intramural stress and strain distributions in the atherosclerotic arteries considering the complexity of the lesion

考虑病变的复杂性，测量动脉粥样硬化动脉的壁内应力和应变分布

基本信息

批准号：
11680834
负责人：
MATSUMOTO Takeo
金额：
$ 2.37万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

To reveal the effects of mechanical factors on the initiation and progression of atherosclerosis, it is important to know the stress and strain distribution in the atherosclerotic lesions as well as the effects of blood flow on the endothelial cells. In this 2-year project, we experimentally induced atherosclerotic lesions in the rabbit thoracic aortas and studied the mechanical environment of the atherosclerotic lesions by measuring their local mechanical properties and local defomation of the aortas during inflation. We first measured local elastic modulus by a pipette aspiration method and studied the relationship between the modulus and the histology quantitatively to find that the atherosclerotic tissue became softer than the normal tissue at the initial stage of the lesion, then became stiffer with the appearance of the smooth muscle cells and calcified tissues. Next, we measured the deformation of the tubular specimen of the aortas during inflation as follows : We made four fine needles penetrate through the wall at an angular interval of about 90゜ as markers and observed the displacement of the needles during inflation from an end of the specimen. Local deformations of the wall were obtained at four circumferential segments held with the two adjacent needles. Strain referring to the stress-free state was obtained for each segment. The strain was not uniform among the segments in the atherosclerotic aorta. The difference among the segments tended to increase with the progression of the disease. Similar measurement performed for human coronary arteries indicated that the segment with thicker plaque had smaller strain. These results indicate that atherosclerotic arteries show marked heterogeneity. Local measurement is indispensable to reveal the mechanical environment of atherosclerotic lesions.

为了揭示力学因素在动脉粥样硬化发生和发展中的作用，了解动脉粥样硬化病变中的应力和应变分布以及血流对内皮细胞的影响是很重要的。在这个为期2年的项目中，我们实验性地诱导了兔胸主动脉粥样硬化病变，并通过测量其局部力学特性和膨胀过程中主动脉的局部变形来研究动脉粥样硬化病变的力学环境。我们首先用吸管抽吸法测量局部弹性模量，并定量研究其与组织学的关系，发现动脉粥样硬化组织在病变初期比正常组织变软，然后随着平滑肌细胞和钙化组织的出现而变硬。接下来，我们如下测量了膨胀过程中动脉的管状样本的变形：我们使四根细针以约90 μ s标记的角度间隔穿透壁，并从样本的一端观察膨胀过程中针的位移。在用两个相邻针固定的四个圆周段处获得了壁的局部变形。获得每个节段的无应力状态应变。在动脉粥样硬化的主动脉段之间的应变是不均匀的。各节段间的差异有随病情进展而增大的趋势。对人类冠状动脉进行的类似测量表明，具有较厚斑块的段具有较小的应变。这些结果表明，动脉粥样硬化动脉表现出显着的异质性。局部测量对于揭示动脉粥样硬化病变的力学环境是必不可少的。