MRB Research Center Magnetic-Resonance-Bavaria, Würzburg, Germany.
Microvasc Res. 2010 Dec;80(3):484-90. doi: 10.1016/j.mvr.2010.05.007. Epub 2010 Jun 4.
ACE inhibition has been shown to improve left ventricular (LV) and myocardial blood flow. Previous data regarding changes in capillary density and angiogenesis during ACE inhibition are controversial. The aim of the following study was to determine myocardial microcirculation and heart function in the rat after coronary stenosis using non invasive MR imaging techniques. MR spin labeling and cine techniques have been performed in female Wistar rats 2weeks after coronary artery stenosis. In one group, animals were treated with quinapril in a dose of 6mg/kg/day. Perfusion, relative blood volume (RBV), LV mass and function were determined non-invasively 2weeks after treatment. Finally, fibrosis and capillary density were analyzed histologically. Additionally, hemodynamic measurements were realized in a further group in order to calculate systemic vascular resistance (SVR). Quinapril resulted in a significant increase in perfusion at rest in the remote and the poststenotic myocardium with improved systolic function and a decrease in SVR compared to the non treated control group. Additionally, maximum perfusion and RBV were slightly elevated whereas capillary density was unchanged among the groups. MRI allows for non-invasive quantification of functional microcirculation and heart function. In addition to the well known effect of ACE inhibition on systolic function, treatment with the tissue specific ACE inhibitor quinapril revealed an important microvascular improvement, especially at arteriolar level. These findings may support the use of tissue ACE inhibitors to improve cardiac microcirculation after ischemia.
ACE 抑制已被证明可改善左心室 (LV) 和心肌血流。关于 ACE 抑制期间毛细血管密度和血管生成变化的先前数据存在争议。本研究的目的是使用非侵入性磁共振成像技术确定冠状动脉狭窄后大鼠的心肌微循环和心脏功能。在冠状动脉狭窄 2 周后，对雌性 Wistar 大鼠进行了 MR 自旋标记和电影技术。在一组中，动物以 6mg/kg/天的剂量接受喹那普利治疗。在治疗 2 周后非侵入性地确定灌注、相对血容量 (RBV)、LV 质量和功能。最后，通过组织学分析纤维化和毛细血管密度。此外，在另一组中进行了血流动力学测量，以计算全身血管阻力 (SVR)。与未治疗的对照组相比，喹那普利可使静息时远程和狭窄后心肌的灌注显著增加，收缩功能改善，全身血管阻力 (SVR) 降低。此外，最大灌注和 RBV 略有升高，而各组之间的毛细血管密度不变。MRI 可实现对功能性微循环和心脏功能的非侵入性定量。除了 ACE 抑制对收缩功能的众所周知的作用外，组织特异性 ACE 抑制剂喹那普利的治疗还显示出重要的微血管改善，特别是在小动脉水平。这些发现可能支持使用组织 ACE 抑制剂改善缺血后心脏微循环。
