Regional Distribution of Diffusible Tracers and Carbonized Microspheres in the Left Ventricle of Isolated Dog Hearts
Regional Distribution of Diffusible Tracers and Carbonized Microspheres in the Left Ventricle of Isolated Dog Hearts
复制标题
离体狗心脏左心室弥散示踪剂和碳化微球的区域分布
DOI：
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发表时间：
1973
影响因子：
20.1
通讯作者：
J. Bassingthwaighte
中科院分区：
文献类型：
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作者：
T. Yipintsoi;W. Dobbs;P. Scanlon;T. Knopp;J. Bassingthwaighte
将不同大小的~(125)I标记的安替比林(I-AP)微球和42KCl或86RbCl以1.3~4.8ml/m in g−_1的血流量注入离体犬的朗道夫灌流非工作心脏的主动脉内。15秒~5分钟后，将左室切成约300个有序碎片，并测定每个示踪剂的量。对于所有的示踪剂，心内膜区域的相对沉积密度通常较高，但在一颗主动脉压和总冠脉流量较低的心脏除外。在三个心脏中，42K和I-AP的沉积基本上是相似的，存在很大的区域差异。这一发现表明，这两种示踪剂要么与流量成比例分布，要么在高流量区域由于较低的跨毛细管萃取而导致42K沉积相对密度的小幅减少，与由于注射后前15-30秒内更快的洗脱而在这些相同区域由于更快的洗脱而减少的I-AP残留分数在定量上相似。大的微球优先沉积在高流量的区域，夸大了区域流动的明显不均一性。较小微球的分布更接近I-AP或42K微球。
Microspheres of different sizes, 125I-labeled antipyrine (I-Ap), and 42KCl or 86RbCl were injected into the aortic inflow of isolated, Langendorff, perfused, nonworking dogs hearts at blood flows of 1.3–4.8 ml/min g−1. After 15 seconds to 5 minutes, the left ventricle was sectioned into about 300 ordered pieces, and the amount of each tracer was determined. For all tracers, the relative density of deposition was generally higher in the endocardial region, except in one heart in which the aortic pressure and the total coronary flow were low. The deposition of 42K and that of I-Ap were essentially similar in three hearts over a large range of regional variation. This finding suggests either that both tracers were distributed in proportion to flow or that a small diminution in relative density of deposition of 42K in high-flow regions due to lower transcapillary extraction was quantitatively similar to a decrease in the residual fraction of I-Ap in these same regions due to faster washout in the first 15–30 seconds after injection. Large microspheres were deposited preferentially in regions of high flow, exaggerating the apparent heterogeneity of regional flows. The distribution of the smaller microspheres was closer to that for I-Ap or 42K.