MOLECULAR AND PARTICULATE DEPOSITIONS FOR REGIONAL MYOCARDIAL FLOWS IN SHEEP
MOLECULAR AND PARTICULATE DEPOSITIONS FOR REGIONAL MYOCARDIAL FLOWS IN SHEEP
复制标题
DOI：
10.1161/01.res.66.5.1328
复制
发表时间：
1990-05-01
影响因子：
20.1
通讯作者：
KROHN, KA
中科院分区：
文献类型：
--
作者：
BASSINGTHWAIGHTE, JB;MALONE, MA;KROHN, KA
微球在小组织区域的沉积不是严格依赖于流动的。与可溶性流动标记2-碘甲基丙咪胺(IDMI)相比，16.5-微米微球的沉积轻微但系统地偏向兔心脏的高流动区域(Bassingthwaighte JB，Malone MA，Moffett T-C，King Rb，Little SE，Link JM，Krohn Ka)。Am J Physiol 1987；253(心圈Physiol 22)：H184-H193)。为了检验较大心脏存在偏见的可能性，在绵羊身上进行了类似的研究。将~(141)Ce和~(103)Ru标记的16.5~µm微球和~(125)I和~(131)I-DMI同时注入5只开胸绵羊的左心房，同时从股动脉获取参比血样。在其他6只绵羊中，使用了一种微球型和一种IDMI。注射后1分钟取出心脏，切成大约254块，平均217毫克，根据同位素计数计算每个示踪剂的区域沉积密度。在五种动物中，两种不同标记的IDMI之间以及两种微球之间的相关性均为>；0.98。在所有11只绵羊中，微球沉积密度与IDMI密度的散点图显示，不同的微球和IDMI具有显著更大的分散性(0.84；r<；0.98)，但不是随机的。微球沉积倾向于在低流动区低于IDMI沉积，在高流动区高于IDMI沉积，这与预期的偏差一致，即在分叉处，微球最有可能进入流量较高的分支。可归因于心内膜/心外膜分布不均的偏倚较少。因此，尽管当感兴趣的区域足够小以至于微球的直径仅为微球的几倍时，微球沉积对于流动似乎是系统性的错误，但对于绵羊和兔子来说，微球足以估计区域流动。
The deposition of microspheres in small tissue regions is not strictly flow dependent. In comparison with the soluble flow marker 2-iododesmethylimipramine (IDMI), deposition of 16.5-.mu.m microspheres was mildly but systematically biased into high flow regions of rabbit hearts (Bassingthwaighte JB, Malone MA, Moffett T-C, King RB, Little SE, Link JM, Krohn KA. Am J Physiol 1987;253 (Heart Circ Physiol 22):H184-H193). To examine the possibility of bias in larger hearts, a similar study was undertaken in sheep. 141Ce- and 103Ru-labeled 16.5-.mu.m microspheres in one syringe and 125I- and 131I-DMI in another syringe were injected simultaneously into the left atrium of five open-chest sheep while obtaining reference blood samples from the femoral artery. In six other sheep, one microsphere type and one IDMI were used. Hearts were removed 1 minute after injection, cut into approximately 254 pieces averaging 217 mg, and regional deposition densities calculated for each tracer from the isotopic counts. Correlations in the five animals between the two differently labeled IDMIs and between the two microspheres were both > 0.98. In all 11 sheep, scatter plots of microsphere deposition densities versus IDMI densities showed that differences microspheres and IDMI had substantially more scatter (0.84 < r < 0.98) but were not random. Microsphere depositions tended to be lower than IDMI depositions in low flow regions and higher in high flow regions, in accord with the expected bias that at a bifurcation a microsphere is most likely to enter the branch with higher flow. There was less bias ascribable to endomyocardial/epicardial maldistribution. Thus, while microsphere depositions appear to err systematically with respect to flow when the regions of interest are small enough that the diameters of their arterioles are only a few times those of the microspheres, microspheres are, in sheep as in rabbits, adequate for estimating regional flows.