Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
Am J Physiol Heart Circ Physiol. 2011 Jan;300(1):H94-H100. doi: 10.1152/ajpheart.00708.2010. Epub 2010 Nov 12.
Endothelial dysfunction precedes the development of morphological atherosclerotic changes and can also contribute to lesion development in cardiovascular diseases. Currently, there is a lack of a single method to determine endothelial function of the entire range of vessel dimensions from aorta to arterioles. Here we assessed endothelial function of a large range of size arteries using a unified isovolumic myograph method. The method maintains a constant volume of fluid in the lumen of the vessel during contraction and relaxation, which are characterized by an increase and a decrease of pressure, respectively. Segments of six aortas, six common femoral arteries, and six mesenteric arteries from rats; six carotid arteries from mice; and six coronary and carotid arteries from pigs were used. The endothelium-dependent dose-response vasorelaxation was determined with endothelium-dependent vasodilators while arterial preconstriction was induced with vasoconstrictors at a submaximal dose. The circumferential midtension during vascular reactivity varied from 43.1 ± 7.9 to 2.59 ± 0.46 mN/mm (from large to small arteries), whereas the circumferential midstress showed a much smaller variation from 217 ± 23.5 to 123 ± 15.3 kPa (in the same range of vessels). We also found that overinflation and axial overelongation compromised endothelium-dependent vasorelaxation to underscore the significance of vessel preload. In conclusion, an isovolumic myograph was used to unify arterial vasoreactivity from large to small arteries and shows the uniformity of wall stress and %tension throughout the range of vessel sizes.
内皮功能障碍先于形态学动脉粥样硬化变化的发展，也可能导致心血管疾病中的病变发展。目前，缺乏一种单一的方法来确定从主动脉到小动脉的整个血管尺寸范围内的内皮功能。在这里，我们使用统一的等容肌描记法评估了大范围大小动脉的内皮功能。该方法在收缩和舒张期间保持血管管腔中的流体体积恒定，这分别表现为压力的增加和减少。使用大鼠的六个主动脉段、六个股总动脉段和六个肠系膜动脉段；来自小鼠的六个颈动脉段；以及来自猪的六个冠状动脉和颈动脉段。通过使用内皮依赖性血管扩张剂来确定内皮依赖性剂量反应性血管舒张，同时在亚最大剂量下使用血管收缩剂诱导动脉预收缩。血管反应性期间的圆周中张力从 43.1 ± 7.9 到 2.59 ± 0.46 mN/mm 不等（从大到小动脉），而圆周中应力的变化要小得多，从 217 ± 23.5 到 123 ± 15.3 kPa（在相同的血管范围内）。我们还发现，过度充气和轴向过长会损害内皮依赖性血管舒张，这突出了血管预负荷的重要性。总之，等容肌描记法用于统一从大到小动脉的动脉血管反应性，并显示出整个血管尺寸范围内壁应力和 %张力的均匀性。
